双模态冲压发动机Ma6性能潜力受燃烧室入口参数影响的灵敏度分析

Sensitivity Analysis of Combustor Incoming Parameters on Dual-Mode Scramjet Performance Potential at Ma6

关键词:  双模态冲压发动机  一维方法  燃烧室入口参数  性能潜力  灵敏度分析

Key words:  Dual-mode scramjet  One-dimensional method  Combustor incoming parameters  Performance potential  Sensitivity analysis

摘要:

为系统掌握燃烧室入口参数对双模态冲压发动机性能潜力的影响，采用双模态冲压发动机燃烧室工作过程的一维分析方法，在飞行马赫数为6的不同燃烧室工作工况(即不同特征马赫数Mac)条件下，保持进气道捕获流量不变，研究了燃烧室入口马赫数Main和总压恢复系数σin对性能潜力(燃料比冲Isp,f)的影响。获得的数据表明，冲压发动机的性能潜力受燃烧室入口马赫数和总压恢复系数两者的综合影响，燃烧室入口马赫数越低、总压恢复系数越高，发动机性能潜力越大；在常见的燃烧室入口参数范围内(入口马赫数∈［2.4 3.5］，入口总压恢复系数∈［0.3 0.7］)，入口马赫数每减小0.1，燃料比冲增加约1.1%～1.8%，入口总压恢复系数越小，影响程度越大；入口总压恢复系数每增大0.1，燃料比冲增大约2.4%～4.0%，入口马赫数越大影响程度越大；存在燃烧室入口条件不同，但是发动机的比冲性能潜力相同的情况。对燃烧室分段过程的损失分析表明，在入口为超声速、加热段为亚声速(特征马赫数不大于1)工况条件下，入口马赫数增加导致燃烧区前激波串损失增大，是比冲性能降低的主要原因；燃烧室特征马赫数越大，燃烧过程导致的损失越大；从燃烧室入口到尾喷管出口全过程总压损失越小，获得的比冲性能越大。推导和拟合了冲压发动机冲量差燃料比冲随燃烧室入口马赫数和总压恢复系数的灵敏度关系式，与被拟合数据的差异在3%以内，该关系式可用于双模态冲压发动机部件参数匹配与流道一体化设计工作。

Abstract:

To obtain a systematic understanding about the effects of supersonic combustor incoming parameters on a Dual-mode scramjet performance potential (fuel specific impulse Isp， f)， one dimensional analysis method is applied to study the relationship between performance and incoming parameters， including Mach number (Main) and total pressure recovery coefficient (σin)， while the flight Mach number is 6， the incoming massflow rate is fixed， and the characteristic Mach number (Mac) in heating sections is varied. Results indicate that the performance potential is influenced synthetically by these incoming parameters. In a common range of the combustor inflow parameters (Main∈［2.4 3.5］， σin∈［0.3 0.7］)， Isp， f increases by 1.1%～1.8% while Main decrease by 0.1. The higher σin is， the greater influence of Main has. Isp， f increases by 2.4%～4.0% while σin increase by 0.1. The higher Main is， the more influence of σin has. There are cases with the same specific impulse but different incoming parameters. Loss analysis for combustor subsections shows that increasing of Main leads to great loss in its pre-combustion shock train process with supersonic incoming flow and subsonic heating process. This is the main reason to make Isp， f decreased. More loss will be deduced in combustion process when Mac increases in heating section. The formulized sensitivity relationship between the potential performance and combustor incoming parameters is deduced. The difference from the original data is less than 3%. The relationship can be used to match the processes between engine components.