Flow and Pressure Drop Characteristics for Various Non-Circular Curved Ducts Used in Automobile HVAC System with Different Bend Angles 2013-01-1645

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.