Evaluate the effectiveness of cylindrical cooling holes embedded in arc trench over flat plate surface using infra-red technology
Year: 2020
Type: conference-paper
Abstract: The present study employed Infra-Red Technology (IRT) to show and measure flat plate surface temperature. Experimental investigation of film cooling holes was achieved. The effect of blowing ratio for the Perspex flat plate samples was obtained using Thermal Image camera and Thermal Wind Tunnel (TWT). A flat plate with (240 mm long x 8 mm height x 120 mm width) was fabricated using the CNC machine. Namely, 9 film cooling holes (4 mm diameter) are placed as one row at a lateral spacing of pitch equal to three times of hole diameter with 35° angle of injection. Infra-Red Technology (IRT) was used to examine the ejected cooling air experimentally through increasing injection BR (BR=0.5, 1 and 1.5). So far, in terms of film cooling performance, the experimental result illustrates noticeable improvement achieved at BR=1 due to a reduction in plat surface temperature. Thermocouple technology was also used in this study by embedding 8 thermocouples in the flat place surface to measure the temperature of the coolant in the midline along the surface. The transient temperature along plate was measured for each BR during the first 500 sec of the test. Consequently, the lower the blowing ratio, the more stable increment in temperature points (gradually increasing) with longer testing time to reach steady state after 1500 sec. Moreover, the cylindrical holes model provides better film cooling efficiency at BR=1 and the arc trench model gave the best enhancement ineffectiveness at BR=0.5 and 1. It was found that, the experimental results were in excellent matching with previous published results. Finally, IRT shows successfully the qualitative temperature distribution on the plate surface.
Authors: Wisam A Ajlan, Harbi A Daud, Nabil J Yasin
Institution: Middle Technical University
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W3048601003