Extended surface convective cooling studies of engine components using the transient liquid crystal technique

Journal article

A heat transfer tunnel used for local convective heat transfer coefficient measurements on liquid crystal instrumented models is described. The tunnel uses the new mesh heater device to produce a good approximation to a step change in the test section flow temperature. A simple analytical model of the cooling performance of cylindrical extended surfaces is derived from empirical relations obtained from the literature. Experiments conducted on a smooth cylinder and selected cylindrical finned geometries are discussed. The use of liquid crystal mapping techniques is shown to provide the full distribution of local heat transfer coefficients across the fin surface. This enables a greater understanding of the convective cooling process than could be obtained from the simple average measurements of h previously reported in the literature. Measurements of the average heat transfer coefficients are found to be as low as a third of the value predicted by correlations. The work shows that correct selection of fin geometry can result in a significant increase in convective cooling performance.

Authors: Neely, A; Ireland, P; Harper, L

• Publisher: Technologisch Instituut
• Journal: Proceedings of the 1997 2nd European Conference on Turbomachinery - Fluid Dynamics and Thermodynamics, Antwerpen, Belgium, 5-7 March 1997
• Pages: 463-474
• Publication date: 1997-01-01
• Language: English