Temperature effects on helium filled soap bubble particle tracking velocimetry.

HFSB;PTV;PIV;temperature;accuracy;error

Michael C. Blum

University:University of Louisville

Department:Mechanical Engineering

关键词: HFSB;    PTV;    PIV;    temperature;    accuracy;    error;   

Others  :  https://ir.library.louisville.edu/cgi/viewcontent.cgi?article=4183&context=etd

美国|英语

来源: The Universite of Louisville's Institutional Repository

【 摘 要 】

Helium Filled Soap Bubble (HFSB) Particle Tracking Velocimetry (PTV) methods are becoming increasingly popular as they provide a low cost, safe option for reliable flow visualization. Several studies have been conducted to understand the accuracy of such systems under normal temperatures and pressures; however, no such studies to date have examined accuracy of HFSB PTV at high temperatures. The goal of this study is to characterize the capability of HFSB PTV methods to visualize air flow through a rectangular duct at elevated temperature. A heated wind tunnel was designed to heat up to 150 m3/h of 25 °C dry air to 150 °C, and Reynolds numbers ranging from 3500 to 17000 were considered. It was determined that bubble survival at temperatures in excess of 65°C was too low to obtain reliable velocity measurements. In the range of temperatures in which HFSBs survived in adequate numbers, it was demonstrated that Stokes’ law was valid and elevated temperatures yielded no significant impact on the ability of HFSBs to trace fluid flow.