Numerical study of the roughness effect on drag coefficients in a flow around a 2D re-entry capsule

Articles in Press

Document Type : Original Article

Authors

• Samira Sourani ¹
• Morteza Bayareh ²
• Alireza Shateri ²

¹ Department of Mechanical Engineering, Shahrekord, University, Shahrekord, Iran

² Department of Mechanical Engineering, Shahrekord University, Shahrekord, Iran

10.22067/jacsm.2025.93726.1333

Abstract

In the design of re-entry capsules, due to the absence of control surfaces, significant attention is always paid to the issue of dynamic stability. This study examines the flow around the re-entry capsule under various flow conditions and the impact of surface roughness on pressure and velocity contours. The flow around the capsule is significantly influenced by aerodynamic factors, including geometric design and surface characteristics. In this investigation, numerical simulations are used to evaluate pressure and velocity variations at different points on the capsule's surface at three different Reynolds numbers. The results indicate that the surface roughness of the capsule can lead to increased friction in the boundary layer and pressure drop in the rear region of the capsule, which affects the drag coefficient and contributes to the formation of vortex regions. The final values of the drag coefficient for Reynolds numbers of 102, 103, and 106 are 1.69, 1.687, and 1.63, respectively, which indicates that the drag coefficient decreases with an increase in the Reynolds number.

Keywords

• Re-entry capsule
• Surface roughness
• Vortex
• Drag coefficient
• Pressure coefficient

Main Subjects

• Aerodynamics

---