この作品は、レオナルドP.チャモロのスタートアップパッケージの一部として機械科学・工学、イリノイ大学アーバナ・シャンペーン校、学部によってサポートされていました。

<ol>
	<li>Wygnanski, I., Fiedler, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Some measurements in the self preserving jet. , (1968).</li><li>Rajaratnam, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Turbulent jets. , (1976).</li><li>Panchapakesan, N., Lumley, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Turbulence+measurements+in+axisymmetric+jets+of+air+and+helium.+Part+1.+Air+jet.">Turbulence measurements in axisymmetric jets of air and helium. Part 1. Air jet.</a> J Fluid Mech. 246, 197-223 (1993).</li><li>Hussein, H. J., Capp, S. P., George, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Velocity+measurements+in+a+high-Reynolds-number,+momentum-conserving,+axisymmetric,+turbulent+jet.">Velocity measurements in a high-Reynolds-number, momentum-conserving, axisymmetric, turbulent jet.</a> J Fluid Mech. 258, 31-75 (1994).</li><li>Yule, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-scale+structure+in+the+mixing+layer+of+a+round+jet.">Large-scale structure in the mixing layer of a round jet.</a> J Fluid Mech. 89, 413-432 (1978).</li><li>Yule, A., Chigier, N., Ralph, S., Boulderstone, R., Venturag, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combustion-transition+interaction+in+a+jet+flame.">Combustion-transition interaction in a jet flame.</a> AIAA Journal. 19, 752-760 (1981).</li><li>Quinn, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Upstream+nozzle+shaping+effects+on+near+field+flow+in+round+turbulent+free+jets.">Upstream nozzle shaping effects on near field flow in round turbulent free jets.</a> Eur J Mech B-Fluid. 25, 279-301 (2006).</li><li>Mi, J., Nathan, G. J., Luxton, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Centreline+mixing+characteristics+of+jets+from+nine+differently+shaped+nozzles.">Centreline mixing characteristics of jets from nine differently shaped nozzles.</a> Exp Fluids. 28, 93-94 (2000).</li><li>Liepmann, D., Gharib, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+streamwise+vorticity+in+the+near-field+entrainment+of+round+jets.">The role of streamwise vorticity in the near-field entrainment of round jets.</a> J Fluid Mech. 245, 643-668 (1992).</li><li>Oh, S. K., Shin, H. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+visualization+study+on+the+effect+of+forcing+amplitude+on+tone-excited+isothermal+jets+and+jet+diffusion+flames.">A visualization study on the effect of forcing amplitude on tone-excited isothermal jets and jet diffusion flames.</a> Int J Energ Res. 22, 343-354 (1998).</li><li>Cenedese, A., Doglia, G., Romano, G., De Michele, G., Tanzini, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=LDA+and+PIV+velocity+measurements+in+free+jets.">LDA and PIV velocity measurements in free jets.</a> Exp Therm Fluid Sci. 9, 125-134 (1994).</li><li>Wang, H., Peng, X., Lin, W., Pan, C., Wang, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bubble-top+jet+flow+on+microwires.">Bubble-top jet flow on microwires.</a> Int J Heat Mass Tran. 47, 2891-2900 (2004).</li><li>Shestakov, M. V., Tokarev, M. P., Markovich, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+Flow+Dynamics+in+a+Turbulent+Slot+Jet:+Time-resolved+Tomographic+PIV+Measurements.">3D Flow Dynamics in a Turbulent Slot Jet: Time-resolved Tomographic PIV Measurements.</a> 17th Int Symp on Applications of Laser Techniques to Fluid Mechanics. , (2014).</li><li>Scarano, F., Bryon, K., Violato, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Time-resolved+analysis+of+circular+and+chevron+jets+transition+by+tomo-PIV.">Time-resolved analysis of circular and chevron jets transition by tomo-PIV.</a> 15th Int Symp on Applications of Laser Techniques to Fluid Mechanics. , (2010).</li><li>Holzner, M., Liberzon, A., Nikitin, N., Kinzelbach, W., Tsinober, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small-scale+aspects+of+flows+in+proximity+of+the+turbulent/nonturbulent+interface.">Small-scale aspects of flows in proximity of the turbulent/nonturbulent interface.</a> Phys Fluids. 19, 071702 (2007).</li><li>Holzner, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Lagrangian+investigation+of+the+small-scale+features+of+turbulent+entrainment+through+particle+tracking+and+direct+numerical+simulation.">A Lagrangian investigation of the small-scale features of turbulent entrainment through particle tracking and direct numerical simulation.</a> J Fluid Mech. 598, 465-475 (2008).</li><li>Chang, T. P., Wilcox, N. A., Tatterson, G. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+image+processing+to+the+analysis+of+three-dimensional+flow+fields.">Application of image processing to the analysis of three-dimensional flow fields.</a> Opt Eng. 23, 283-287 (1984).</li><li>Racca, R., Dewey, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+automatic+particle+tracking+in+a+three-dimensional+flow+field.">A method for automatic particle tracking in a three-dimensional flow field.</a> Exp Fluids. 6, 25-32 (1988).</li><li>Maas, H. G., Gruen, D., Papantoniou, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+tracking+velocimetry+in+three-dimensional+flows.">Particle tracking velocimetry in three-dimensional flows.</a> Exp Fluids. 15, 133-146 (1993).</li><li>Kasagi, N., Matsunaga, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+particle+tracking+velocimetry+measurement+of+turbulence+statistics+and+energy+budget+in+a+backward-facing+step+flow.">Three-dimensional particle tracking velocimetry measurement of turbulence statistics and energy budget in a backward-facing step flow.</a> Int J Heat Fluid Fl. 16, 477-485 (1995).</li><li>Virant, M., Dracos, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+PTV+and+its+application+on+Lagrangian+motion.">3D PTV and its application on Lagrangian motion.</a> Meas Sci Technol. 8, 1539 (1997).</li><li>Willneff, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> A spatio-temporal matching algorithm for 3 D particle tracking velocimetry. , (2003).</li><li>Rosi, G. A., Sherry, M., Kinzel, M., Rival, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterizing+the+lower+log+region+of+the+atmospheric+surface+layer+via+large-scale+particle+tracking+velocimetry.">Characterizing the lower log region of the atmospheric surface layer via large-scale particle tracking velocimetry.</a> Exp Fluid. 55, 1-10 (2014).</li><li>Fu, S., Biwole, P. H., Mathis, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+Tracking+Velocimetry+for+indoor+airflow+field:+A+review.">Particle Tracking Velocimetry for indoor airflow field: A review.</a> Build Environ. 87, 34-44 (2015).</li><li>Kolaas, J., Jensen, A., Mielnik, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualization+and+measurements+of+flows+in+micro+silicon+Y-channels.">Visualization and measurements of flows in micro silicon Y-channels.</a> Eur Phys J E. 36, 1-11 (2013).</li><li>G&#252;lan, U., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+study+of+aortic+flow+in+the+ascending+aortavia+Particle+Tracking+Velocimetry.">Experimental study of aortic flow in the ascending aortavia Particle Tracking Velocimetry.</a> Exp Fluids. 53, 1469-1485 (2012).</li><li>Mei, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Velocity+fidelity+of+flow+tracer+particles.">Velocity fidelity of flow tracer particles.</a> Exp Fluids. 22, 1-13 (1996).</li><li>Tropea, C., Yarin, A. L., Foss, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Springer handbook of experimental fluid mechanics. 1, (2007).</li><li>Melling, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracer+particles+and+seeding+for+particle+image+velocimetry.">Tracer particles and seeding for particle image velocimetry.</a> Meas Sci Technol. 8, 1406 (1997).</li><li>Hering, F., Leue, C., Wierzimok, D., J&#228;hne, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+tracking+velocimetry+beneath+water+waves.+Part+I:+visualization+and+tracking+algorithms.">Particle tracking velocimetry beneath water waves. Part I: visualization and tracking algorithms.</a> Exp Fluids. 23, 472-482 (1997).</li><li>Biferale, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lagrangian+structure+functions+in+turbulence:+A+quantitative+comparison+between+experiment+and+direct+numerical+simulation.">Lagrangian structure functions in turbulence: A quantitative comparison between experiment and direct numerical simulation.</a> Phys Fluids. 20, 065103 (2008).</li><li>L&#252;thi, B., Tsinober, A., Kinzelbach, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lagrangian+measurement+of+vorticity+dynamics+in+turbulent+flow.">Lagrangian measurement of vorticity dynamics in turbulent flow.</a> J Fluid mech. 528, 87-118 (2005).</li><li>Hoyer, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3d+scanning+particle+tracking+velocimetry.">3d scanning particle tracking velocimetry.</a> Exp Fluids. 39, 923-934 (2005).</li><li>Kim, J. -. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Three-dimensional particle tracking velocimetry for turbulence applications. , (2015).</li><li>L&#252;thi, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Some+aspects+of+strain,+vorticity+and+material+element+dynamics+as+measured+with+3D+particle+tracking+velocimetry+in+a+turbulent+flow.">Some aspects of strain, vorticity and material element dynamics as measured with 3D particle tracking velocimetry in a turbulent flow.</a> ETH Z&#252;rich. , (2002).</li><li>Pope, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Turbulent flows. , (2000).</li></ol>

著者は、彼らが競合する経済的利害関係を持っていないことを宣言します。

<html> 3D-PTVは下層大気25、室内空気分布26でこのような大規模乱流運動として乱流の様々な複雑な物理現象を解明するための大きな可能性を秘めている、または拍動性は、多くの他の中大動脈トポロジ28に流れます。しかし、その利点と限界についての理解だけでなく、経験がその可能性を最大限にすることが不可欠です。トライアルフレームレート、照明光源、G＆Bレ?...

乱流ジェット流は、エンジニアリング用途に遍在しています。このような流れの詳細な特性は、電子マイクロスケールデバイスに大規模な環境放電システムから及ぶ実用上の問題の広い範囲で非常に重要です。 4 -ための広範なアプリケーションの数に与える影響を、ジェットフローは、深さ1に研究されています。熱線流速計4を含むいくつかの実験技術- 8は 、レーザードップラー流速計（LDV）4,9 - 12、及び粒子画像流速測定（PIV）12を- 16は 、噴流を特徴付けるために使用されてきたレイノルズ数と境界の広い範囲に流れます条件。最近、いくつかの研究では、ジェットの乱流/非乱流インタフェースは17、18を流れて勉強する3D-PTVを使用して作られてきました。 3D-PTVは、複雑な乱流Fiのを記述するために特に適した技術であります異なる視点からELDより。これは、マルチビュー立体視を用いて、基準のラグランジュフレームにボリューム内の粒子軌道の再構成を可能にします。技術は最初チャン19によって導入され、さらにRaccaとデューイ20によって開発されました。 24 -それ以来、多くの改良は、3D-PTVアルゴリズムと実験21日に行われています。これらの成果と以前の作品では、システムが正常に4 MX 2 MX 2メートル25、室内の気流場26のドメインにこのような大規模な流体運動など様々な流体現象を研究するために使用されてきた、拍動は27と大動脈の血流28を流れ、 。 3D-PTV計測の動作原理は、データ収集システムのセットアップ、記録/前処理、キャリブレーション、3D対応、時間追跡および後処理から成ります。正確なキャリブレーションは、粒子の位置を正確に検出することが可能秒。以上の3つの画像ビューで検出された粒子の対応はエピポーラ幾何学に基づいた3Dパーティクル位置の再構築を可能にします。連続する画像フレームからの結合は、粒子の軌跡S（t）を定義する一時的な追跡をもたらします。 3D-PTVシステムの最適化は、多粒子トレーサビリティの尤度を最大にするために不可欠です。 最適化の最初のステップは、高速カメラ、照明源とシード粒子の特徴を含む適切なデータ収集システムを取得することです。調査体積の大きさに伴ってカメラの解像度は、画素サイズと単一の画素よりも大きくする必要があり、従って、必要なシード粒子のサイズを定義します。検出された粒子の重心は、輝度21で重み付け粒子画素の平均位置を取ることによってサブピクセル精度で推定されます。カメラのフレームレートは密接associatありますレイノルズ数と検出された粒子をリンクする機能とエド。より高いフレームレートが速い流れまたは平均画像間の変位は粒子の平均分離を超える場合、追跡がより困難になるので、粒子の多くを解決することを可能にします。 シャッター速度、絞り、感度は画像キャプチャで考慮すべき3つの要因です。シャッター速度は、粒子の重心位置の不確実性を低下させ、粒子、周りにぼかし最小限にするのに十分高速である必要があります。カメラの絞りは、ボリュームの外側に粒子を検出する確率を低減するために調査体積のフィールドの深さに調整されるべきです。カメラの最大感度が固定されているので、フレームレートが増加すると、粒子を照明​​するために要求される必要な光は、それに応じて増加するはずです。 PIVとは異なり、複雑な光学設定と高出力レーザーは厳密に限り、光源が十分にスキャットであ​​るとして、3D-PTVで必要とされていませんカメラにトレーサー粒子から結。連続LEDやハロゲンライトは同期21の必要性を回避良い費用対効果の高いオプションです。 3D-PTVでは、他のオプティカルフロー測定技術と同様に、トレーサー粒子速度は、局所瞬間流速29であると仮定されます。しかし、これはnullを直径と慣性の理想的なトレーサーのための唯一のケースです。トレーサー粒子は、カメラによって捕捉されるのに十分大きくなければなりません。有限の粒子の忠実度は、粒子の緩和時間スケール比と関心の乱流構造の時間尺度、すなわち 、ストークス数S tで決定することができます。一般的に、S tは S Tの1よりも実質的に小さくなければならない≤0.1フロートラッキング誤差は1％未満である30。より綿密な議論がメイらに記載されています29 - 。31 </sup&gt;。 3D-PTVの実験のための推奨される粒径は、光源とカメラの感度によって異なります。ハロゲンまたは照明光源としてLEDが点灯して、比較的大きな粒子が使用される（ 例えば 、50〜200ミクロン）32、より小さな粒子（ 例えば 1~50ミクロン）33に対し、 図34は、高出力レーザー（ 例えば、80〜100ワットで使用することができCWレーザー）。所定の波長の光に対して高い反射率を有する粒子が、ハロゲンライトの下でコーティングされた銀のように、画像にその足跡を増幅することができます。播種密度は、成功した3D-PTV測定のための別の重要なパラメータです。粒子の過剰な数が対応関係を確立し、追跡中の曖昧さを引き起こす一方で、いくつかの粒子は、軌道の低い数になります。対応関係を確立する上で曖昧さが重なり、粒子と定義されたエピポーラ線に沿って複数の候補を検出することが含まれます。追尾処理において、高いseedinによる曖昧<html> G濃度があるため、粒子の比較的短い平均分離を発生しました。 第二段階は、画像品質を向上させるために、記録/前処理で最適な設定です。そのようなゲインと黒レベル（G＆B）のような写真の設定は、画像品質を最適化する上で重要な役割を果たしています。ゲインは、画像の明るさを増幅するのに対し、黒レベルは、画像の最も暗い部分の明るさのレベルを定義します。 G＆Bレベルのわずかな変化が著しく、トレーサビリティの可能性に影響を与えることができます。実際には、高G＆Bは、画像の上に、明るく、最終的には、カメラのセンサーを破損する恐れがあります。これを説明するために、流れの再構築にG＆Bレベルの影響も、この記事で検討されています。前処理工程では、画像は、粒子からの光散乱を強調するために、ハイパスフィルタを用いてフィルタリングされます。画素サイズ、グレースケールを調査体積内の粒子の検出を最大にするように調整されます。 T &quot;&gt;最適化の第三工程は、エピポーラ幾何、カメラパラメータ（焦点距離、主点、及び歪み係数）、および屈折率の変化に基づいて立体視画像化の正確なキャリブレーションである。このプロセスは、3Dを最小にするために不可欠です基準目標点の再構成エラー。エピポーラ幾何学は、対象画像からと傾斜角度（カメラと呼び掛けボリュームとの間の）相対距離を使用しています。調査体積を介してカメラビューに沿って屈折率の変化は質量の手順に基づいて考慮することができますら 21は、この実験では、規則的に分布ターゲットポイントと3D階段状構造は、標的として使用されます。 2つだけの画像が3次元粒子位置を決定するために必要とされるが、3D-PTV実験では、通常、複数のカメラを曖昧21を減少させるために使用されます。複数のハイスピー​​ドカメラで高価なセットアップする代わりに、viのですEWの3D-PTVの使用についてホイヤーらによって提案されたスプリッタ、35、最近の生物医学的用途のためにGulean ら 28によって適用されます。ビュースプリッタは、ピラミッド型のミラー（ここに至って主鏡）と4つの調整可能なミラー（副鏡ここに至って）で構成されています。この研究では、4つのビュースプリッタと単一のカメラが4台のカメラからの立体画像化を模倣するために使用しました。システムは、直径、dは H = 1 cmで再 ≈7,000ラグランジアンからとパイプジェットの中間流れ場を特徴付けるために使用され、オイラーは、ジェット原点から下流の周りに14.5から18.5の直径でフレーム。

<table border="0" cellpadding="0" cellspacing="0" width="749">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">ImageOps</td>
			<td style="width:119px;">CAMMC4082</td>
			<td style="width:407px;">High-speed camera</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">ImageOps</td>
			<td style="width:119px;">FBD-4XCXP6</td>
			<td>Frame Grabber</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:223px;">Potters Industries LLC</td>
			<td style="width:119px;">AG-SL150-30-TRD</td>
			<td>Seeding Paritcles</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:223px;">Upstate Technical Equipment CO.,INC</td>
			<td style="width:119px;">MISNOR-STP-6-S-CL</td>
			<td>Camera appliation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Photrack AG</td>
			<td style="width:119px;"></td>
			<td>Customized part and necessary if performing 3D-PTV with one camera</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">General Electrics&#160;</td>
			<td style="width:119px;">23719</td>
			<td>Light source</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:223px;">OpenPTV(http://www.openptv.net)</td>
			<td style="width:119px;"></td>
			<td>Open source particle tracking software (Note: available as a service for anyone who wants to use it without all the installation mess or computer power availability problems).</td>
		</tr>
	</tbody>
</table>

three-dimensional particle tracking velocimetry for turbulence applications: case of a jet flow

3D-PTVは、画像シーケンスの立体記録を用いて、三次元での粒子の組のラグランジュ経路を追跡することを目的と定量流量測定技術です。 4ビュースプリッタと高速度カメラからなる3D-PTVトポロジの基本的なコンポーネント、機能、制約および最適化のヒントは、この資料に記載され議論されています。技術は、 再 ≈7,000に円形噴流の中間流れ場（5 &lt;X / D &lt;25）に適用されます。オイラーフレーム内のラグランジュフロー機能や乱流の量はジェット起源の下流10の直径の周りに、ジェットコアからの様々な半径方向距離であると推定されています。ラグランジュのプロパティは軌道、選択された粒子の速度と加速度だけでなく、Frenet-Serret方程式から得られる流路の曲率を含みます。 10に位置するクロスプレーンでのジェットコア軸周りの3D速度と乱流場の推定ジェットの下流の直径は、文献と比較して、大規模な流れ方向速度運動のパワースペクトルは、ジェットコアから様々な半径方向距離で得られます。

写真とセットアップの概略図は、 図 1及び2に示されています。較正ターゲットは、基準マークは、 図 3に示されている図スプリッタおよび3Dキャリブレーションの再構成に反映しました。認識されたキャリブレーションターゲットのRMSは、流れ方向のx、スパン方向y及び深さz方向に7.3ミクロン、5.7ミクロ...

Watch this Scientific Journal Video about Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow at JoVE.com

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

四ビュースプリッターと高速度カメラに基づいた三次元粒子追跡速度測定（3D-PTV）システムは、ここに記載されています。技術は、下流≈7,000レイノルズ数Reで10直径の近傍に円管からの噴流に適用されます。

ジェット流の場合：乱流のアプリケーションのための3次元粒子追跡流速

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic ...

three-dimensional-particle-tracking-velocimetry-for-turbulence

Research

Education

JoVE Journal

JoVE Core

Engineering

Physics

Civil Engineering

Unit 1

Flow in Pipes

Motion in Two or Three Dimensions

SCIENTISTS IN ACTION

12.1K ビュー.  University of Illinois at Urbana-Champaign. 四ビュースプリッターと高速度カメラに基づいた三次元粒子追跡速度測定（3D-PTV）システムは、ここに記載されています。技術は、下流≈7,000レイノルズ数Reで10直径の近傍に円管からの噴流に適用されます。 

ビデオ: Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

Echo Particle Image Velocimetry

The transport of mass, momentum, and energy in fluid flows is ultimately determined by spatiotemporal distributions of the fluid velocity field.1 Consequently, a prerequisite for understanding, predicting, and controlling fluid flows is the capability to measure the velocity field with adequate spatial and temporal resolution.2 For velocity measurements in optically opaque fluids or through optically opaque geometries, echo particle image velocimetry (EPIV) is an attractive diagnostic technique to generate "instantaneous" two-dimensional fields of velocity.3,4,5,6 In this paper, the operating protocol for an EPIV system built by integrating a commercial medical ultrasound machine7 with a PC running commercial particle image velocimetry (PIV) software8 is described, and validation measurements in Hagen-Poiseuille (i.e., laminar pipe) flow are reported.
For the EPIV measurements, a phased array probe connected to the medical ultrasound machine is used to generate a two-dimensional ultrasound image by pulsing the piezoelectric probe elements at different times. Each probe element transmits an ultrasound pulse into the fluid, and tracer particles in the fluid (either naturally occurring or seeded) reflect ultrasound echoes back to the probe where they are recorded. The amplitude of the reflected ultrasound waves and their time delay relative to transmission are used to create what is known as B-mode (brightness mode) two-dimensional ultrasound images. Specifically, the time delay is used to determine the position of the scatterer in the fluid and the amplitude is used to assign intensity to the scatterer. The time required to obtain a single B-mode image, t, is determined by the time it take to pulse all the elements of the phased array probe. For acquiring multiple B-mode images, the frame rate of the system in frames per second (fps) = 1/&delta;t. (See 9 for a review of ultrasound imaging.)
For a typical EPIV experiment, the frame rate is between 20-60 fps, depending on flow conditions, and 100-1000 B-mode images of the spatial distribution of the tracer particles in the flow are acquired. Once acquired, the B-mode ultrasound images are transmitted via an ethernet connection to the PC running the PIV commercial software. Using the PIV software, tracer particle displacement fields, D(x,y)[pixels], (where x and y denote horizontal and vertical spatial position in the ultrasound image, respectively) are acquired by applying cross correlation algorithms to successive ultrasound B-mode images.10 The velocity fields, u(x,y)[m/s], are determined from the displacements fields, knowing the time step between image pairs, &Delta;T[s], and the image magnification, M[meter/pixel], i.e., u(x,y) = MD(x,y)/&Delta;T. The time step between images &Delta;T = 1/fps + D(x,y)/B, where B[pixels/s] is the time it takes for the ultrasound probe to sweep across the image width. In the present study, M = 77[&mu;m/pixel], fps = 49.5[1/s], and B = 25,047[pixels/s]. Once acquired, the velocity fields can be analyzed to compute flow quantities of interest.

An echo particle image velocimetry (EPIV) system capable of acquiring two-dimensional fields of velocity in optically opaque fluids or through optically opaque geometries is described, and validation measurements in pipe flow are reported.

エコー粒子画像流速測定法

The transport of mass, momentum, and energy in fluid flows is ultimately determined by spatiotemporal distributions of the fluid velocity field.1 ...

工学

High-resolution, High-speed, Three-dimensional Video Imaging with Digital Fringe Projection Techniques

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses triangulation between matching points in two views of the same scene at different angles to compute depth.&#160;However, unlike a stereo-based method, DFP uses a digital video projector to replace one of the cameras1. The projector rapidly projects a known sinusoidal pattern onto the subject, and the surface of the subject distorts these patterns in the camera&#8217;s field of view. Three distorted patterns (fringe images) from the camera can be used to compute the depth using triangulation.
Unlike other 3D measurement methods, DFP techniques lead to systems that tend to be faster, lower in equipment cost, more flexible, and easier to develop.&#160;DFP systems can also achieve the same measurement resolution as the camera.&#160;For this reason, DFP and other digital structured light techniques have recently been the focus of intense research (as summarized in1-5). Taking advantage of DFP, the graphics processing unit, and optimized algorithms, we have developed a system capable of 30&#160;Hz 3D video data acquisition, reconstruction, and display for over 300,000 measurement points per frame6,7.&#160;Binary defocusing DFP methods can achieve even greater speeds8.
Diverse applications can benefit from DFP techniques. Our collaborators have used our systems for facial function analysis9, facial animation10, cardiac mechanics studies11, and fluid surface measurements, but many other potential applications exist.&#160;This video will teach the fundamentals of DFP techniques and illustrate the design and operation of a binary defocusing DFP system.

This video describes the fundamentals of digital fringe projection techniques, which provide dense 3D measurements of dynamically changing surfaces.&#160;It also demonstrates the design and operation of a high-speed binary defocusing system based on these techniques.

デジタル干渉縞投影技術と高分解能、高速、三次元ビデオ画像

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses ...

Process of Making Three-dimensional Microstructures using Vaporization of a Sacrificial Component

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material fabrication techniques are able to mimic the complexity of these structures while maintaining scalability. The Vaporization of a Sacrificial Component (VaSC) process is able to do so. This process uses sacrificial fibers as a template to form hollow, cylindrical microchannels embedded within a matrix. Tin (II) oxalate (SnOx) is embedded within poly(lactic) acid (PLA) fibers which facilitates the use of this process. The SnOx catalyzes the depolymerization of the PLA fibers at lower temperatures. The lactic acid monomers are gaseous at these temperatures and can be removed from the embedded matrix at temperatures that do not damage the matrix. Here we show a method for aligning these fibers using micromachined plates and a tensioning device to create complex patterns of three-dimensionally arrayed microchannels. The process allows the exploration of virtually any arrangement of fiber topologies and structures.

The Vaporization of a Sacrificial Component (VaSC) process is used to fabricate microvascular structures. This procedure uses sacrificial poly(lactic) acid fibers to form hollow microchannels with precise 3D geometric positioning provided by laser micromachined guide plates.

犠牲成分の蒸発を用いた三次元微細構造を作る過程

Vascular structures in natural systems are able to provide high mass transport through high surface areas and optimized structure. Few synthetic material ...

High-speed Particle Image Velocimetry Near Surfaces

Multi-dimensional and transient flows play a key role in many areas of science, engineering, and health sciences but are often not well understood. The complex nature of these flows may be studied using particle image velocimetry (PIV), a laser-based imaging technique for optically accessible flows. Though many forms of PIV exist that extend the technique beyond the original planar two-component velocity measurement capabilities, the basic PIV system consists of a light source (laser), a camera, tracer particles, and analysis algorithms. The imaging and recording parameters, the light source, and the algorithms are adjusted to optimize the recording for the flow of interest and obtain valid velocity data. 
Common PIV investigations measure two-component velocities in a plane at a few frames per second. However, recent developments in instrumentation have facilitated high-frame rate (&gt; 1 kHz) measurements capable of resolving transient flows with high temporal resolution. Therefore, high-frame rate measurements have enabled investigations on the evolution of the structure and dynamics of highly transient flows. These investigations play a critical role in understanding the fundamental physics of complex flows.
A detailed description for performing high-resolution, high-speed planar PIV to study a transient flow near the surface of a flat plate is presented here. Details for adjusting the parameter constraints such as image and recording properties, the laser sheet properties, and processing algorithms to adapt PIV for any flow of interest are included.

A procedure for studying transient flows near boundaries using high-resolution, high-speed particle image velocimetry (PIV) is described here. PIV is a non-intrusive measurement technique applicable to any optically accessible flow by optimizing several parameter constraints such as the image and recording properties, the laser sheet properties, and analysis algorithms.

表面近くの高速粒子画像流速

Multi-dimensional and transient flows play a key role in many areas of science, engineering, and health sciences but are often not well understood. The ...

Visualization of High Speed Liquid Jet Impaction on a Moving Surface

Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds between 0 and 25 m/sec) and a spinning disk device (for examining surface speeds between 15 and 100 m/sec). The air cannon linear traverse is a pneumatic energy-powered system that is designed to accelerate a metal rail surface mounted on top of a wooden projectile. A pressurized cylinder fitted with a solenoid valve rapidly releases pressurized air into the barrel, forcing the projectile down the cannon barrel. The projectile travels beneath a spray nozzle, which impinges a liquid jet onto its metal upper surface, and the projectile then hits a stopping mechanism. A camera records the jet impingement, and a pressure transducer records the spray nozzle backpressure. The spinning disk set-up consists of a steel disk that reaches speeds of 500 to 3,000 rpm via a variable frequency drive (VFD) motor. A spray system similar to that of the air cannon generates a liquid jet that impinges onto the spinning disc, and cameras placed at several optical access points record the jet impingement. Video recordings of jet impingement processes are recorded and examined to determine whether the outcome of impingement is splash, splatter, or deposition. The apparatuses are the first that involve the high speed impingement of low-Reynolds-number liquid jets on high speed moving surfaces. In addition to its rail industry applications, the described technique may be used for technical and industrial purposes such as steelmaking and may be relevant to high-speed 3D printing.

Two experimental devices for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device and a spinning disk device. The apparatuses are used to determine optimal approaches to the application of liquid friction modifier (LFM) onto rail tracks for top-of-rail friction control.

表面移動に高速液体ジェット宿便の可視化

Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds ...

Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their behavior for single stages of a process or even an entire process. For the simulation with occurring particle-particle and particle-wall contacts, the value of the coefficient of restitution is required. It can be determined experimentally. The coefficient of restitution depends on several parameters like the impact velocity. Especially for fine particles the impact velocity depends on the air pressure and under atmospheric pressure high impact velocities cannot be reached. For this, a new experimental setup for free-fall tests under vacuum conditions is developed. The coefficient of restitution is determined with the impact and rebound velocity which are detected by a high-speed camera. To not hinder the view, the vacuum chamber is made of glass. Also a new release mechanism to drop one single particle under vacuum conditions is constructed. Due to that, all properties of the particle can be characterized beforehand.

The coefficient of restitution is a parameter that describes the loss of kinetic energy during collision. Here, a free-fall setup under vacuum conditions is developed to be able to determine the coefficient of restitution parameter for particles in micrometer range with high impact velocities.

真空条件下で反発係数の測定のための実験のセットアップの開発

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their ...

Methods for Measuring the Orientation and Rotation Rate of 3D-printed Particles in Turbulence

Experimental methods are presented for measuring the rotational and translational motion of anisotropic particles in turbulent fluid flows. 3D printing technology is used to fabricate particles with slender arms connected at a common center. Shapes explored are crosses (two perpendicular rods), jacks (three perpendicular rods), triads (three rods in triangular planar symmetry), and tetrads (four arms in tetrahedral symmetry). Methods for producing on the order of 10,000 fluorescently dyed particles are described. Time-resolved measurements of their orientation and solid-body rotation rate are obtained from four synchronized videos of their motion in a turbulent flow between oscillating grids with R&#955; = 91. In this relatively low-Reynolds number flow, the advected particles are small enough that they approximate ellipsoidal tracer particles. We present results of time-resolved 3D trajectories of position and orientation of the particles as well as measurements of their rotation rates.

We use 3D printing to fabricate anisotropic particles in the shapes of jacks, crosses, tetrads, and triads, whose alignments and rotations in turbulent fluid flow can be measured from multiple simultaneous video images.

乱流で3Dプリント粒子の配向および回転速度を測定するための方法

Experimental methods are presented for measuring the rotational and translational motion of anisotropic particles in turbulent fluid flows. 3D printing ...

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm2, but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample&#39;s properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 &#181;m all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

For this study synchrotron radiation micro-tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron&#39;s high flux and brightness the sample was imaged in just 3 min&#160;with an 8.7 &#181;m spatial resolution.

マルチスケール三次元マイクロエレクト​​ロニクスパッケージを調査するために放射光マイクロトモグラフィーを用いて、

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data ...

Three-Dimensional Ultrasonic Needle Tip Tracking with a Fiber-Optic Ultrasound Receiver

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. When visualization is lost, the medical device can cause trauma to critical tissue structures. Here, a method to track the needle tip during ultrasound image-guided procedures is presented. This method involves the use of a fiber-optic ultrasound receiver that is affixed within the cannula of a medical needle to communicate ultrasonically with the external ultrasound probe. This custom probe comprises a central transducer element array and side element arrays. In addition to conventional two-dimensional (2D) B-mode ultrasound imaging provided by the central array, three-dimensional (3D) needle tip tracking is provided by the side arrays. For B-mode ultrasound imaging, a standard transmit-receive sequence with electronic beamforming is performed. For ultrasonic tracking, Golay-coded ultrasound transmissions from the 4 side arrays are received by the hydrophone sensor, and subsequently the received signals are decoded to identify the needle tip&#39;s spatial location with respect to the ultrasound imaging probe. As a preliminary validation of this method, insertions of the needle/hydrophone pair were performed in clinically realistic contexts. This novel ultrasound imaging/tracking method is compatible with current clinical workflow, and it provides reliable device tracking during in-plane and out-of-plane needle insertions.

Accurate and efficient visualization of invasive medical devices is extremely important in many ultrasound-guided minimally invasive procedures. Here, a method for localizing the spatial position of a needle tip relative to the ultrasound imaging probe is presented.

三次元超音波針の先端光ファイバー超音波受信機と追跡

Ultrasound is frequently used for guiding minimally invasive procedures, but visualizing medical devices is often challenging with this imaging modality. ...

Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques

Numerous problems in scientific and engineering fields involve understanding the kinematics of particles in turbulent flows, such as contaminants, marine micro-organisms, and/or sediments in the ocean, or fluidized bed reactors and combustion processes in engineered systems. In order to study the effect of turbulence on the kinematics of particles in such flows, simultaneous measurements of both the flow and particle kinematics are required. Non-intrusive, optical flow measurement techniques for measuring turbulence, or for tracking particles, exist but measuring both simultaneously can be challenging due to interference between the techniques. The method presented herein provides a low cost and relatively simple method to make simultaneous measurements of the flow and particle kinematics. A cross section of the flow is measured using a particle image velocimetry (PIV) technique, which provides two components of velocity in the measurement plane. This technique utilizes a pulsed-laser for illumination of the seeded flow field that is imaged by a digital camera. The particle kinematics are simultaneously imaged using a light emitting diode (LED) line light that illuminates a planar cross section of the flow that overlaps with the PIV field-of-view (FOV). The line light is of low enough power that it does not affect the PIV measurements, but powerful enough to illuminate the larger particles of interest imaged using the high-speed camera. High-speed images that contain the laser pulses from the PIV technique are easily filtered by examining the summed intensity level of each high-speed image. By making the frame rate of the high-speed camera incommensurate with that of the PIV camera frame rate, the number of contaminated frames in the high-speed time series can be minimized. The technique is suitable for mean flows that are predominantly two-dimensional, contain particles that are at least 5 times the mean diameter of the PIV seeding tracers, and are low in concentration.

The technique described herein offers a low cost and relatively simple method to simultaneously measure particle kinematics and turbulence in flows with low particle concentrations. The turbulence is measured using particle image velocimetry (PIV), and particle kinematics are calculated from images obtained with a high-speed camera in an overlapping field-of-view.

フロー イメージング技術を用いた粒子運動と乱流の同時測定

Numerous problems in scientific and engineering fields involve understanding the kinematics of particles in turbulent flows, such as contaminants, marine ...