A Study of Aerodynamic Pressure Drag and Skin Friction Resistance Comparison on ICE 3 Train under Different Yaw-angles

Aerodynamic Pressure Drag and Skin Friction Resistance

Abstract

The chief purpose of this research was to compare the aerodynamic pressure drag and train body skin friction resistance contribution on ICE 3 HST vehicles, which run at 320km/h speed. It has also determined the flow character of each car on the train according to its position. The two main factors of external HST body resistance have been studied in different yaw-angle conditions of open embankment infrastructure. The full-scale test is conducted to verify the computer, mesh, and a serious numerical simulation to the performed investigation of aerodynamic loads for comparison pressure drag and frictional resistances. Has used PHOENICS VR CFD numerical test approach, and validated by EN14067-6:2010 standard report and experimental test values in Table 9. For applying in the LES turbulence model, a blockage ratio of 3.015% and at Reynold’s maximum number of 1.120E+08.
From the detailed flow analysis, the research found out that pressure drag is the dominant air resistance compared to train body skin friction. Especially, it showed that the frictional resistance became much less when the wind attack angles were different from zero. Particularly, are from drag components, the maximum pressure drag in the x-axis recorded when a wind yaw-zero, and which is decreased as the wind yaw-angle attack increases. That is illustrated in Table 8 from the range of 22.45% for a minimum of 10.53%. But, the side force is increased by 66.36% to a maximum of 97.38%. The lift force was recorded higher at yaw-zero and dropped in a very noticeable effect from case-1 to case-2 tests by 98.48%. On the other hand, it started to increase gradually while the wind yaw-angle increased, which was in the range of 21.64% to a maximum of 69.15%. Hence, the study predicted that the running stability of the ICE3 train worsen when the wind attack yaw-angle increased. This is owing to lift and side force coefficients drastically raised. The study clearly has provided that the aerodynamics pressure drag is dominant over friction resistance when an HST runs under an incompressible medium.