基于HyShot发动机的试验介质影响数值研究

Numerical study of test medium effects based on HyShot scramjet

为了研究试验介质对超燃冲压发动机流场和性能的影响,以含双方程k-ωSST湍流模式的质量平均NavierStokes方程为控制方程,对Hyshot发动机流场进行了数值模拟,对比研究了根据不同模拟准则、来流加热方式获得的来流条件对发动机流场及组合参数的影响。结果表明:直接燃烧加热方式改变了来流的组分和热力学特性;两种模拟(总焓模拟、静温模拟)准则中,依据总焓模拟准则给出的流场参数间的一致性较好;四种污染来流加热方式中,采用燃烧甲烷、补充氧气加热方式、依据两种模拟准则给出的来流参数之间相互一致,可减少对计算结果的偏差性修正;同一模拟准则中,基于不同加热方式提供的来流,计算给出的流场参数间的差异呈现系统性(整体性)偏差;对基于流场参数的组合参数来讲,马赫数和冲量函数系数受模拟准则、来流加热方式的影响程度小于比冲量受相关影响的程度,冲量函数系数可为作为发动机性能的一个关联参量。

In order to investigate the influence of test medium on the flow field and the performance of scramjet combustor,the cold and chemical non-equilibrium flow field in a Hyshot scramjet combustor has been simulated numerically by using the Favre-Averaged Navier-Stokes equations with the two-equation k-ωSST turbulence model.According to two test flow matching criterions and four airflow heating schemes,the effects of the inflow conditions are studied comparatively.The results indicate that:1)the burning fuel in the airflow upstream of the test chamber changes the composition and thermodynamic property of test medium;2)the consistent condition of test mediums obtained by matching airflow total enthalpy is better than that obtained by matching airflow static temperature;3)based on the two test flow matching criterions,the compositions and thermodynamic properties of the test medium obtained by burning methane(CH 4)and supplying oxygen(O 2)are consistent with each other,and the heating scheme can help reduce the correction of calculation or test results;4)in the cases with the same test flow match condition,the flow parameters in the scramjet combustor simulated the basis of the entrance conditions with four different fueled combustion heating schemes show systematical difference;5)regrding the combination parameters,the test flow matching criterions and heating schemes have more influence on the specific impulse than the Mach number and impulse function coefficient,and the impulse function coefficient can be used as a correlation parameter for the scramjet performance.