Computation of nonequilibrium viscous flows in arc-jet wind tunnel nozzles
Computation of nonequilibrium viscous flows in arc-jet wind tunnel nozzles
复制标题
电弧喷射风洞喷嘴中非平衡粘性流的计算
DOI：
10.2514/6.1994-254
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
T. Gokcen
中科院分区：
文献类型：
--
作者：
T. Gokcen
数值求解了缩放锥喷管内的轴对称Navier-Stokes方程。本文采用双温热化学模型的非平衡方程描述振动激发、部分离解和电离的空气。通过将计算的流量与在膨胀电弧喷射喷嘴中获得的实验数据进行比较，对该公式进行了评价。在出口与喉道面积比为625和8100的锥形喷管中获得的两组实验数据包括5 ~ 95大气压的压力和5 ~ 10 MJ/kg的压差。计算结果与喷管出口的局部质量流量、皮托管压力和静态壁压测量值吻合较好。对于低压油藏条件下，计算与实验数据的比较表明，壁面催化性是非常重要的预测物种的摩尔分数在喷嘴出口处，因为气相化学是冻结。目前的计算高估了原子氧浓度，这反过来又导致振动温度的预测不足。
The axisymmetric Navier-Stokes equations are numerically solved for air flows in converging-diverging conical nozzles. A nonequilibrium formulation with a two-temperature thermochemical model has been employed for vibrationally excited, partially dissociated and ionized air. Evaluations of the formulation is made through comparisons of the computed flow quantities with the experimental data obtained in expanding arc-jet nozzle flows. Two sets of experimental data obtained in conical nozzles with geometric exit-to-throat area ratios of 625 and 8100 cover reservoir pressures ranging from 5 to 95 atm and enthalpies from 5 to 10 MJ/kg. The computed results are in good agreement with local mass flux, Pitot pressure, and static wall pressure measurements at the nozzle exit. For low pressure reservoir conditions, comparisons of computations with the experimental data indicate that the wall catalycity is very important in predicting species mole fraction at the nozzle exit since gas phase chemistry is frozen. The current computations overpredict the atomic oxygen concentrations which in turn results in underprediction of the vibrational temperature.