Visualization Studies of Heat and Mass Transfer in Forced Flow He II

本文涉及流动可视化和粒子图像测速(PIV)技术在He II内的传热传质研究中的应用，目的是获得研究He II内微观尺度热流体问题的能力，以便在实际应用中更好地利用流体作为冷却剂。这项工作将首先集中在将合适的中性密度粒子引入He II逆流/强制流动通道的实验中。待研究的中性粒子包括固体H2/D2和中空玻璃微球。一旦粒子播撒技术被开发出来，PIV实验将研究He II通道的微尺度流体动力学。这些实验将在配备了光学通道的低温恒温器中进行。如果成功，这将是第一次在He II上演示PIV，也将是唯一一次在逆流或强迫流He II中进行粒子成像研究。这也将清楚地表明PIV在低温热流体研究中的价值。

Title: Visualization Studies of Heat and Mass Transfer in Forced Flow He IIPI: Steven W. Van Sciver, Florida State UniversityProposal Number: CTS-0001411AbstractThis work involves the application of flow visualization and particle image velocimetry (PIV) techniques to studies of heat and mass transfer in He II. The purpose is to obtain the capability to investigate microscopic scale thermal fluid issues in He II, so that the fluid can be better utilized as a coolant in applications. The effort will first focus on techniques to introduce suitable neutral density particles into experiments with a He II counterflow/forced flow channel. Neutral particles to be investigated include solid H2/D2 and hollow glass microspheres. Once particle seeding techniques have been developed, PIV experiments will investigate the microscale fluid dynamics of the He II channel. The experiments will be performed in a cryostat equipped with optical access. If successful, this will be the first demonstration of PIV in He II and the only particle imaging study in counterflow or forced flow He II. It will also be a clear indication of the value of PIV for cryogenic thermal fluid studies.