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Non-circular ducts with strong curvature is commonly used in automobile HVAC system. The geometric cross section of the duct along with the bend angle plays a significant role in pressure drop. The present work aims at computationally analyzing the effect of eight different geometric cross-section ducts with different bend angles ranging from 0 degree to 135 degree on flow and pressure drop characteristics. A comparative study with different duct geometry and the bend angle is performed using fluent code. The effect of duct geometric cross section on secondary velocity and the total pressure loss coefficient for various duct geometries are discussed in detail. It is observed that the curvature of outer wall, slope of top wall and bottom wall plays a significant role in total pressure drop. It is found that the Rectangle-B and Triangle ducts are more sensitive to bend angle whereas Rectangle-A and Semicircle-A are least sensitive to bend angle in terms of total pressure drop.

A computational study is reported on flow and heat transfer from single row of slot air jets impinging on an automobile windshield surface. The effects of jet-to-jet spacing and jet exit to windshield spacing are computationally analyzed for a three values of Reynolds number. There is a significant variation in pressure and heat transfer along the stagnation zone and the entire windshield surface for all the configurations tested. It is observed that the average heat transfer in the stagnation zone reduces by about 9 % when c/d is increased from 2 to 4. However the average heat transfer for the entire windshield increases with c/d as well as h/d. The maximum increase is average heat transfer for the entire windshield is found to be 33% for the case with c/d=4, h/d=5.6 than that of the case with c/d=2, h/d=3.6.