轴对称收-扩喷管内外流场一体化数值模拟

基于求解Navier-Stokes方程组对某航空发动机的轴对称固定几何收-扩喷管进行了六种工况的内外流场一体化数值模拟,计算出了喷管的流量系数和推力系数。结果表明,收-扩喷管超音速射流,在地面工况下表现为过膨胀特征,在高空不同工况下表现为欠膨胀特征,形成了复杂的激波系和膨胀波系。在欠膨胀状态,随着落压比的增大,喷管的流量系数无明显变化,但推力系数显著减小。另外,从理论解出发,计算了前面各种工况的喷管出口气动性能参数,并与数值模拟结果进行了对比分析,验证了数值模拟结果的可靠性。

Numerical simulation on combination flow field for axisymmetric convergent-divergent nozzle

Based on solving Navier-Stokes equations, the numercial simulation on combination flow field for axisymmetric converge- divergengt nozzle of certain aeroengine in six real working conditions were carried out. Meanwhile, the flux coefficient and thrust coefficient were figured out. The results showed that at the state of ground, the supersonic jet was overexpanded, while it appeared to be underexpanded under other high altitude state, there were complex shock and expansion wave. At the state of underexpansion, with the increase of NPR (nozzle pressure ratio), the flux coefficient had no marked change, while the thrust coeffiecient dropped dramatically. In addition, aerodynamic performance parameters of the nozzle exit were obtained according to theoretical solution, and then the reliability of the numerical simulation results was verified by comparing with the theoretical solution results.