侧板构型对二维高超声速进气道启动性能的影响

对侧板前掠和侧板后掠两种构型的二维高超声速进气道开展了自由射流试验和数值模拟,考察了侧板构型对进气道启动性能的影响。结果表明,侧板前掠进气道的启动性能要明显优于后掠构型。通过对壁面压力分布、油流试验和数值模拟结果进行分析,发现侧板后掠进气道不启动流场大规模流动分离位于底板一侧,而前掠侧板对底板附近的流动分离具有限制作用,使得前掠构型不启动流场大规模分离形成于外罩一侧。外罩一侧边界层更薄,抵抗反压能力更强,更不容易发生分离,这正是造成前掠构型启动性能更优的原因。

Effect of Sidewall Geometry on Starting Characteristics of Two-dimensional Hypersonic Inlet

Two-dimensional hypersonic inlets with a forward-swept sidewall and an aft-swept sidewall are tested experimentally and simulated numerically to examine the effect of sidewall geometry on the starting characteristics of a two-dimensional hypersonic inlet.The result shows that the forward-swept sidewall inlet exhibits significantly better capability of self-starting.The bottom wall pressure distribution,surface oil flow pattern and numerical result all reveal that the unstarted flowfield structures of the two inlets are quite different.Largescale flow separation occurs at the bottom wall side in the unstarted flowfield of an aft-swept sidewall inlet,while it is at the cowl side in the unstarted flowfield of a forward-swept sidewall inlet because of the constraint on the separation bubble by the forward-swept sidewall leading edge.The cowl side boundary layer is much thinner than the bottom wall side boundary layer and it can resist stronger reverse pressure gradient before theseparation occurred.That accounts for the fact that the forward-swept sidewall inlet has better starting characteristics.