Name: uncoupling coriolis force and rotating buoyancy effects on full-field heat transfer properties of a rotating channel
Uploaded: 2018-10-05T12:30:00
Description: Watch this Scientific Journal Video about Uncoupling Coriolis Force and Rotating Buoyancy Effects on Full-Field Heat Transfer Properties of a Rotating Channel at JoVE.com

目前的研究工作是由台湾科学技术部在赠款 94-2611-e-022-001、国安 95-2221-e-022-018、国安理事会 96-2221-e-022-015MY3 和国安理事会 97-2221-e 022-013-MY3 的资助下进行的。

注: 旋转测试设施、数据采集、数据处理和模拟燃气轮机转子叶片内部冷却通道的传热测试模块的详细信息在我们以前的工作29,30,31 ,32。
1. 传热试验的准备
<ol><li>根据燃气轮机转子叶片的目标操作条件, 从稀土、 Ro和步进等方面制定实验条件。</li>
	<li>用方程...

<ol>
	<li>Morris, W. 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> Heat transfer and fluid flow in rotating coolant channels. , ISBN 0471101214 (1981).</li><li>Morris, W. 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+rotating+facility+to+study+heat+transfer+in+the+cooling+passage+of+turbine+rotor+blades.">A rotating facility to study heat transfer in the cooling passage of turbine rotor blades.</a> Journal of Power and Energy. 210 (1), 55-63 (1996).</li><li>Wagner, J. H., Johnson, B. V., Graziani, R. A., Yeh, F. 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C., Chopra, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heat+transfer+in+trailing+edge,+wedge-shaped+cooling+channels+under+high+rotation+numbers.">Heat transfer in trailing edge, wedge-shaped cooling channels under high rotation numbers.</a> ASME Journal of Heat Transfer. 130 (7), 1-11 (2008).</li><li>Liou, T. M., Chen, M. Y., Tsai, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluid+flow+and+heat+transfer+in+a+rotating+two-pass+square+duct+with+in-line+90-deg+ribs.">Fluid flow and heat transfer in a rotating two-pass square duct with in-line 90-deg ribs.</a> ASME Journal of Turbomachinery. 124 (2), 260-268 (2002).</li><li>Chang, S. W., Liou, T. M., Yang, T. L., Hong, G. 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H., Parres, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-dimensional+heat+transfer+distribution+of+a+rotating+ribbed+channel+at+different+Reynolds+numbers.">Two-dimensional heat transfer distribution of a rotating ribbed channel at different Reynolds numbers.</a> ASME Journal of Turbomachinery. 137 (3), (2015).</li><li>Chang, S. W., Yang, T. L., Liou, T. M., Fang, H. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heat+transfer+in+rotating+scale-roughened+trapezoidal+duct+at+high+rotation+numbers.">Heat transfer in rotating scale-roughened trapezoidal duct at high rotation numbers.</a> Applied Thermal Engineering. 29 (8), 1682-1693 (2009).</li><li>Liou, T. M., Chang, S. W., Chen, J. S., Yang, T. L., Lan, Y. 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GT2016-56413, Turbomachinery Technical Conference and Exposition: Heat Transfer. 5 (B), V05BT16A006 1~10 (2016).</li><li>Morris, W. D., Chang, S. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+experimental+study+of+heat+transfer+in+a+simulated+turbine+blade+cooling+passage.">An experimental study of heat transfer in a simulated turbine blade cooling passage.</a> International Journal of Heat Mass Transfer. 40 (15), 3703-3716 (1997).</li><li>Chang, S. W., Liou, T. -. 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在红外热像仪检测旋转通道的壁温度时, 流体温度由热电偶测量。由于驱动旋转钻机的交流电动机的替代磁场诱发电位干扰热电偶测量, 因此必须采用直流电机驱动旋转试验台。
加热通道出口面上的流体温度分布不均匀。建议在旋转通道的现有平面上至少五个热电偶来测量局部流体的出口温度。特别是, 这些热电偶测量的流体温度安装在流动通道是受离心力的力量在旋转试验?...

当热力学定律通过提高涡轮进入温度来决定燃气轮机发动机的特定功率和热效率时, 一些热引擎部件, 如涡轮叶片, 容易受到热损伤。燃气轮机转子叶片的内部冷却允许涡轮进入温度超过叶片材料的蠕变阻力的温度限制。但是, 内部冷却通道的配置必须符合刀片式服务器的配置文件。特别是, 冷却剂在转子叶片内旋转。对于运行中的燃气轮机转子叶片具有如此苛刻的热工况, 有效的叶片冷却方案对于保证结构的完整性至关重要。因此, 旋转通道的局部传热特性对于有效利用有限的冷却液流是很重要的。在实际的发动机条件下, 获得适用于内部冷却通道设计的有用的传热数据, 对于测量某一模拟冷却通道内的燃气轮机转子叶片。
转速在 1万 rpm 以上的旋转大大改变了燃气轮机转子叶片内旋转通道的冷却性能。这种旋转通道的发动机条件的识别是允许使用相似定律。旋转时, 通过推导相对于旋转参照系的流动方程, 可以揭示控制径向旋转通道内传输现象的无量纲群。莫里斯1导出了相对于旋转参照系的动量守恒方程:
<img alt="Equation 1" src="/files/ftp_upload/57630/57630eq1.jpg">(1)
在方程 (1) 中, 局部流体速度, v̄, 与位置向量, r̄相对于一个参考框架旋转的角度速度, ω, 受科氏加速度的影响, 从 2 (ωxv̄),解耦向心浮力, β(ttref) (ωxωxr̄), 驱动压电-公制压力梯度<img alt="Equation 16" src="/files/ftp_upload/57630/57630eq16.jpg"> </img>, 和流体动态粘度, ν。参考流体密度, ρref, 被称为预定义流体参考温度T参考, 这是典型的局部流体体积温度的实验。如果机械能的不可逆转的转换到热能是微不足道的, 能量守恒等式减少到:
<img alt="Equation 2" src="/files/ftp_upload/57630/57630eq2.jpg">(2)
第一项方程 (2) 是通过处理特定焓直接与局部流体温度, T, 通过恒定比热, Cp得到的。由于加热旋转通道中流体温度变化引起的流体密度扰动, 对流体在方程 (1) 中与向心加速度连接时, 流体的运动速度和轴向旋转通道中的温度场耦合。同时, 在调整转速的同时, 科里奥利和向心加速度也随之变化。因此, 科里奥利力和旋转浮力对流体速度和温度场的影响是自然耦合的。
无量纲形式的方程 (1) 和 (2) 揭示了控制旋转通道内热对流的流动参数。在旋转通道上采用基本均匀热流, 局部流体体积温度, tb, 在流向方向上线性增加, s, 从参考入口水平, tref。局部流体体积温度被确定为Tref + τs, 其中τ是流体体积温度在流动方向上的梯度。下列无量纲参数的替换:
<img alt="Equation 3" src="/files/ftp_upload/57630/57630eq3.jpg">(3)
<img alt="Equation 4" src="/files/ftp_upload/57630/57630eq4.jpg">(4)
<img alt="Equation 5" src="/files/ftp_upload/57630/57630eq5.jpg">(5)
<img alt="Equation 6" src="/files/ftp_upload/57630/57630eq6.jpg">(6)
<img alt="Equation 7" src="/files/ftp_upload/57630/57630eq7.jpg">(7)
在方程 (1) 和 (2) 中, V均值、 N和d分别代表流速、旋转速度和通道水力直径的平均流, 导出无量纲流动量和能量方程, 作为方程 (8) 和 (9) 分别。
<img alt="Equation 8" src="/files/ftp_upload/57630/57630eq8.jpg">(8)
<img alt="Equation 9" src="/files/ftp_upload/57630/57630eq9.jpg">(9)
显然, 方程 (9) 中的η是反渗透2βτdR的函数, 分别被称为雷诺、旋转和浮力数. 将惯性和科里奥利力的比值量化的罗斯贝波数字等价于等式 (8) 中的逆旋转数。
当tb 在旋转通道中被计算为tref + τs的情况下, 受均匀热流的作用, τ值可以作为qf/(mCpL) 进行评价. f、 m和L分别为对流加热功率、冷却液质量流量和通道长度。因此, 无量纲局部流体体积温度, ηb, 等于s/d和通道壁上的无量纲温度, ηw, 屈服 [(twtb )/Qf] [mCp] [L/d] +s/d。随着对流换热速率的定义为Qf/(twtb), 无量纲壁-流体温差, ηwηb, 是通过方程 (10) 可转换成局部努塞尔数, 其中ζ为加热区和通道截面积的无量纲形函数。
<img alt="Equation 10" src="/files/ftp_upload/57630/57630eq10.jpg">(10)
用一组预定义的几何图形和水动力和热边界条件, 确定了控制旋转通道局部努塞尔数的无量纲群:
<img alt="Equation 11" src="/files/ftp_upload/57630/57630eq11.jpg">(11)
<img alt="Equation 12" src="/files/ftp_upload/57630/57630eq12.jpg">(12)
<img alt="Equation 13" src="/files/ftp_upload/57630/57630eq13.jpg">(13)
通过实验测试, 调整转速, N, 为不同的Ro产生传热数据的科氏力的各种力量不可避免地改变向心加速度, 从而, 相对强度的旋转浮力。此外, 从旋转通道收集的一组传热数据总是受有限程度的旋转浮力效应的影响。为了揭示科里奥利力和浮力对旋转通道传热性能的影响, 需要通过后处理程序将Ro和布对其性能的影响解耦 ,是包含在目前的实验方法。
燃气轮机转子叶片内旋转通道的发动机和实验室流动条件可由Re、 Ro和步进的范围指定。莫里斯2报告了通过燃气轮机转子叶片冷却液流动的典型发动机条件, 以及允许在实际发动机条件附近进行实验的旋转试验装置的建造和调试..根据莫里斯2总结的现实引擎条件,图 1构造了燃气轮机转子叶片旋转冷却器通道的Re、 Ro和步进范围的实际操作条件。在图 1中, 发动机最坏情况的指示被称为发动机运行状态的最高转速和最高密度比。在图 1中, 较低的极限和最坏的发动机运行条件分别出现在最低和最高的发动机速度。在5000到 2万 rpm 的情况下, 测量一个旋转通道的全速运行速度是非常困难的。然而, 基于相似性定律, 实验室规模的测试已经进行了在减少的转速, 但有几个尝试, 以提供全面覆盖的实际发动机Re, Ro和步范围。作为一种创新的实验方法, 美国宇航局3、4、5、6的主机项目采用高压试验, 在预定的Re中增加流体密度。为了通过降低平均流体速度来扩展Ro范围。在这方面,稀土、 Ro和布的具体关系, 气体常数, Rc和粘度, μ的理想气体, 是相关的:
<img alt="Equation 14" src="/files/ftp_upload/57630/57630eq14.jpg">(14)
<img alt="Equation 15" src="/files/ftp_upload/57630/57630eq15.jpg">(15)
为使实验室条件进入与发动机条件的标称对应,如图 1所示, 转速、 N、冷却液压力、 P、通道水力直径、 d、旋转半径、 R和壁-液温差, ttb, 需要控制, 以配合实际的Re, Ro和步范围。显然, 扩大ro范围的最有效方法之一是增加通道水力直径, 因为ro与d2成正比。由于实验室传热试验在现实的N是非常困难的, 冷却剂压力, P, 在技术上更容易提高, 以扩大Ro范围;即使Ro与P成正比。基于这一理论背景, 本实验方法的设计理念是通过对旋转试验通道的最大通道水力直径进行加压, 提高Ro的性能。随着ro范围的增加,步进的范围也随之扩展, 因为步进与ro2成正比。在图 1中, 所采用的实验室测试条件产生的旋转通道的传热数据也包括3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29. 如图 1所示, 现有的传热数据对现实引擎条件的覆盖率仍然有限, 特别是在所需的步进范围内。图 1中所描述的开放和有色固体符号分别是尖和全场传热实验。如图 1所示, 大部分的传热数据与冷却应用到燃气轮机转子叶片1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24,25,26是点测量使用热电偶方法。墙体传导效应对测量墙体导电热流和流体壁面温度的影响, 破坏了热电偶测量转换后的传热数据质量。此外, 传热测量1,2,3,4,5,6,7, 8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24,25,26使用热电偶方法不能检测旋转表面的二维传热变化。利用现有的实验方法29、30、31、32, 对旋转通道壁上的全场努塞尔数分布进行检测是允许的。用0.1 毫米厚的不锈钢箔与毕号 > > 1 的壁传导效应最小化, 通过本实验方法产生加热功率, 允许从加热箔到冷却液流的一维导热。特别是, 采用瞬态液晶技术和热电偶法, 不允许获得涉及Ro和步进效应的全场传热数据。采用目前稳态液晶热成像方法19, 可检测到的温度范围为35-55 摄氏度, 使传热数据的生成具有逼真的密度比。
利用流动参数控制旋转通道内的热对流, 以证明图 1中所见的真实引擎条件的完全覆盖尚未实现, 因此需要获取全场热传输数据现实的发动机条件不断敦促。本实验方法能同时检测到科里奥利力和旋转浮力效应, 产生全场传热。这些议定书的目的是协助调查人员设计一个与实际的旋转通道的全场传热测量有关的实验策略。与目前实验方法所独有的参数分析方法一样, 允许对对其分离和相互依存的反渗透和布效应进行传热相关性的生成. 
本文介绍了一种实验方法, 旨在产生与实际燃气轮机发动机条件类似的流动条件的旋转通道的二维传热数据, 但在更低的转速下运行实验室。介绍了在实际发动机条件下获取传热数据时, 选择转速、试验通道的水力直径和壁-液温度差范围的方法。介绍了红外热成像系统的标定试验、热损标定试验和旋转传热试验台的运行情况。本文介绍了引起传热测量的重要不确定因素, 以及科里奥利力和浮力对旋转通道传热特性的解耦过程, 并以选择性结果表明了目前的实验方法。

<table>
	<tbody>
		<tr>
			<td>Rotating test rig</td>
			<td>In-house made</td>
			<td></td>
			<td>Design by this research group</td>
		</tr>
		<tr>
			<td>Heat transfer test module</td>
			<td>In-house made</td>
			<td></td>
			<td>Design by this research group</td>
		</tr>
		<tr>
			<td>Mass flow meter</td>
			<td>Eldride Product, Inc.</td>
			<td>3100301-01-01 
			359-1007</td>
			<td></td>
		</tr>
		<tr>
			<td>Infrared thermography system</td>
			<td>NEC P384A-8</td>
			<td>3100401-04 
			3127A-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Instrumentation slip ring</td>
			<td>Michigan Scientific SR36M</td>
			<td>3100506-62 
			3553-372</td>
			<td></td>
		</tr>
	</tbody>
</table>

uncoupling coriolis force and rotating buoyancy effects on full-field heat transfer properties of a rotating channel

提出了一种探索轴向旋转通道传热特性的实验方法。通过对旋转参照系的动量和能量方程的参数分析, 确定了旋转通道中传输现象的特征控制流参数。基于这些无量纲流方程, 提出了将测试模块的设计、实验程序和数据分析联系在一起的实验策略, 试图揭示出孤立的科里奥利力和浮力对热的影响。传输性能。利用不同几何形状旋转通道测量的选择性结果, 说明了科里奥利力和旋转浮力的影响。在不同的旋转通道中, 科里奥利力和旋转浮力的影响具有几个共同的特征, 而与流动方向、通道形状和热布置的关系则发现了独特的传热特征。传输增强设备。无论旋转通道的流动配置如何, 所提出的实验方法都能使物理一致性的传热相关性得到发展, 从而能够对分离和相互依存的科里奥利力进行评估, 并旋转浮力对旋转通道传热性能的影响。

与图 1所示的模拟实验室条件相比, 旋转燃气轮机叶片内部冷却液流动的实际操作条件是从Re、 Ro和步进。数据点下落在现实引擎情况使用当前实验方法总结在协议11,14,17,20,21。虽然全场传热数据比从旋转通道测量的尖传热数据更有用...

Watch this Scientific Journal Video about Uncoupling Coriolis Force and Rotating Buoyancy Effects on Full-Field Heat Transfer Properties of a Rotating Channel at JoVE.com

Uncoupling Coriolis Force and Rotating Buoyancy Effects on Full-Field Heat Transfer Properties of a Rotating Channel

在这里, 我们提出了一个实验方法, 以解耦的科里奥利力和旋转浮力效应的全场传热分布的旋转通道。

解耦科里奥利力和旋转浮力对旋转通道全场传热性能的影响

An experimental method for exploring the heat transfer characteristics of an axially rotating channel is proposed. The governing flow parameters that ...

该方法有助于回答传热领域关键问题，包括许多额定到内部冷却的涡轮转子叶片。该技术的主要优点是采集了全场传热数据和建议的减数据方法。这些能够揭示科里奥利折叠和旋转浮力对局部传热特性的单独和相互依存的影响。演示程序将是余国清，蔡伟玲和洪大申。我实验室的三个研究生该协议要求使用由电机驱动的轴组成的旋转钻机。轴驱动支持测试模块的旋转平台。它还具有旋转平衡的配重。红外摄像机可扫描测试模块。此分解视图示意图中描述了用于数据收集的测试模块的功能。构造时，Teflon 框架、侧壁、分隔板以及顶部和背面板有助于定义具有 S 形入口和出口支脚的方形两个过去通道。模块底座连接到旋转平台。在实验中，不锈钢箔端壁携带电流产生加热助焊剂。铜板有助于将铝箔放置到位。空气孔室提供压力气流通过基地稍微远离入口腿的中心线。最后，来自出口腿的排气也通过底座。一旦组装并到位，外露箔端壁是旋转中的前端壁。在安装的测试模块上，准备测量热发射率。红外摄像机和测试模块之间有加热箔。建立用于加热的电气连接。访问离测试模块最近的铝箔侧面。在铝箔中心的那一侧安装校准的热电偶。接下来将注意力转向摄像机对面的箔面。将一层薄薄的黑色油漆喷洒到热电偶对面的此侧，准备此侧。现在，在数据收集过程中，使用外壳将摄像机隔离在加热箔中。将电力馈送至加热箔，以形成对称流场。一旦系统处于稳定状态，通过热电偶和红外热成像测量温度。使用不同的加热器电源重复测量。完成测量后，从铝箔上取下热电偶。准备好钻机进行传热测试。这包括用于加压测试通道的设备。准备好调整平衡重量，以建立钻机的平衡。首先验证或建立旋转钻机的静态平衡。一旦实现，转子将保持在它设置的任何角度位置。对于动态平衡，以所需的恒定速率启动钻机旋转。开始红外成像并查看捕获的图像。当钻机未保持动态平衡时，测量中的热图图像不稳定。要达到动态平衡，逐步调整配重。当实现动态平衡时，在运行条件下将有一个稳定的热图像。从旋转钻机上卸下测试模块，并将其安装到长凳上。接下来访问模块冷却液通道。有保温材料可用，在这种情况下绝缘纤维。用隔热材料将冷却液通道填充到测试模块。在这里，通道已足够填充，以完成协议中的下一步操作。重新组装测试模块，并准备重新安装钻机。重新连接仪器电缆中的所有电源。将测试模块返回到旋转钻机，施加加热电源并设置测量条件。监测墙温，通常超过三个小时。两个时间点的温度绘制在热图像下方。当温度变化小于 0.3 开尔文时，记录墙壁的环境温度和加热器功率。进行多次测量，同时系统地改变加热、转速和方向。完成操作后，将模块带回工作台上，在再次将其安装在钻机上之前，先将其拆下绝缘材料。接下来，使用测试模块执行传热测试。开始为实验开发的电子表格。在相应的单元格中，定义与测试模块关联的几何参数。设置时，启动冷却液流进入测试通道。在电子表格中，输入环境和流体温度、冷却液质量流速、大气压力和测量冷却液静态压力的测量值。软件计算雷诺数字并显示它。如果它不是所需的雷诺数，则更改冷却液质量流速。然后重新输入测量参数以查找新的雷诺数。建立雷诺编号后，激活热成像系统。接下来，供应和调节加热功率，以设置墙壁温度。通过验证时壁温度剖面是否平坦，检查温度是否达到预定义值的稳定状态。在电子表格中，输入扫描区域的平均壁温。还要输入加热电压和加热电流。对于基线测试，设置条件后保存数据以进行后期处理。对于旋转传热测试，通过激活电机开始旋转继续。在电子表格中输入轴的旋转速度。软件将确定当前条件的旋转编号。调整旋转速度以获取目标旋转编号。为了在稳定状态条件下实现所需的雷诺和符号数，可能需要微调冷却液流速。转速和加热功率数次。保存所有旋转的传热数据以进行后期处理。继续系统地收集实验参数不同值的数据。在这些具有不同雷诺数的冷却液流的 S 通道测试模块的图像中，由于涡流引起的离心力，Nusselt 数存在空间变化。这些图反映了 S 通道模块前导和尾随端壁上的平均传热性能。旋转到静态 Nuselt 编号比作为浮力编号的函数从下面到上方一个前缘壁。对于后缘壁，比率永远不会低于 1。请注意，对于固定的旋转编号和不同的雷诺数，规范化的 Nuselt 数字在小范围内变化。不同的通道类型有不同的行为。对于给定的旋转数，外推到零浮力会由于前壁浮力消失的科里奥利力而产生传热水平。类似的分析适用于后墙。以下是在消失浮力时旋转到静态 Nuselt 数比的变化，作为不同通道几何的旋转编号的函数。数据显示，未耦合的科里奥利力对前缘和后缘端壁区域平均传热特性的影响。这些数据表明浮力数对旋转通道传热特性的影响取决于旋转数。因此，该方法可以深入了解铸轮转子叶片内旋转通道的冷却性能。它也可以应用于其他系统，如富芯电机的月化冷却。通常，由于从旋转表面进行传热测量非常困难，因此对此方法或循环的个体进行新测量。一旦掌握，这项技术可以在100小时内完成，如果它执行得当。在尝试此步骤时，必须记住不断检查冷却液流量是否泄漏。开发后，该技术为铸轮机发动机领域的研究人员探索转子叶片中Nuselt编号分布的全领域铺平了道路。观看此视频后，您应该清楚地了解如何在旋转通道和涡轮转子叶片的旋转通道和应用中解开科里奥利斯折叠和旋转浮力的耦合效果。

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SCIENTISTS IN ACTION

Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy

质子转移和蛋白质构象动力学的光敏蛋白的时间分辨步进扫描傅立叶变换红外光谱

Monitoring the dynamics of protonation and protein backbone conformation changes during the function of a protein is an essential step towards ...

科研

工程学

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping

冲红灯光感受器原子力显微镜使用PeakForce定量纳米机械性能映射

Atomic force microscopy (AFM) uses a pyramidal tip attached to a cantilever to probe the force response of a surface. The deflections of the tip can be ...

Electroactive Polymer Nanoparticles Exhibiting Photothermal Properties

电活性聚合物纳米粒子参展光热特性

A method for the synthesis of electroactive polymers is demonstrated, starting with the synthesis of extended conjugation monomers using a three-step ...

Laser-induced Forward Transfer of Ag Nanopaste

银纳米糊膏的激光诱导正向传输

Over the past decade, there has been much development of non-lithographic methods1-3 for printing metallic inks or other functional materials. Many of ...

Ice Generation and the Heat and Mass Transfer Phenomena of Introducing Water to a Cold Bath of Brine

冰生成和传热传质现象将水引入到盐水冷水浴

We demonstrate a method for the study of the heat and mass transfer and of the freezing phenomena in a subcooled brine environment. Our experiment showed ...

Magnetically Induced Rotating Rayleigh-Taylor Instability

磁感应旋转瑞利 - 泰勒不稳定性

Classical techniques for investigating the Rayleigh-Taylor instability include using compressed gasses1, rocketry2 or linear electric motors3 to reverse ...

Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source

量子干涉效应在硅谐振环光子源测量

Silicon photonic chips have the potential to realize complex integrated quantum information processing circuits, including photon sources, qubit ...

Pool-Boiling Heat-Transfer Enhancement on Cylindrical Surfaces with Hybrid Wettable Patterns

在圆柱面池沸腾传热强化与混合可湿性模式

In this study, pool-boiling heat-transfer experiments were performed to investigate the effect of the number of interlines and the orientation of the ...

Measurements of Local Instantaneous Convective Heat Transfer in a Pipe - Single and Two-phase Flow

管道单、两相流局部瞬时对流换热的测量

This manuscript provides step by step description of the manufacturing process of a test section designed to measure the local instantaneous heat transfer ...

Measurement of Dynamic Force Acted on Water Strider Leg Jumping Upward by the PVDF Film Sensor

PVDF 薄膜传感器对水黾腿跳起动力的测量

This study aimed to make an explanation for the phenomenon in nature that water strider usually jumps or glides on the water surface easily but quickly, ...