Soyuz: Do you know the coefficient drag and lift to drag ratio are during reentry?

Question

I've been learning Python as a hobby the last two years. I like spaceflight too. Therefore I wrote this code to simulate the reentry of a Soyuz. I'd appreciate some feedback: https://github.com/fra-mar/soyuz_reentry But what I couldn't find was reliable data about the Soyuz's drag coefficient or the lift to drag ratio. For the Cd I found values ranging from 0.188 to 1.26 and for the L/D 0.38 to 0.5.

Answer 1

The best estimate I have found online is from a China Academy of Aerospace Aerodynamics paper using CFD. The paper is available on ScienceDirect (free I think?), the $C_D$ & $L/D$ are about 1.3 and 0.25, respectively, at a trimmed angle of attack (Mach = 5).

It should be noted that the focus on the paper is not on obtaining accurate aerodynamic coefficients, but rather looking at their change w.r.t. surface recession (ablation).

Full Reference:

Xu Guowu, Zhou Weijiang, Chen Bingyan, Zhan Huiling, Yang Yunjun, Effect of Recession on the Re-entry Capsule Aerodynamic Characteristic, Procedia Engineering, Volume 99, 2015, Pages 377-383, ISSN 1877-7058, https://doi.org/10.1016/j.proeng.2014.12.550.