球型收敛调节片喷管静态内性能数值研究

Numerical study on static internal performance of spherical convergent flap nozzles

关键词:  航空航天推进系统  球型收敛调节片喷管  矢量推力  内特性

Key words:  Aerospace propulsion system  Spherical convergent flap nozzle  Vector thrust  Internal performance

摘要:

基于CFD数值计算软件,针对喉部宽高比为2.083的球型收敛调节片喷管,进行了矢量与非矢量状态下的内性能数值研究。考察了在不同俯仰和偏航矢量状态下,喷管推力系数、流量系数的变化及落压比对气动矢量角的影响。结果表明:俯仰和偏航两种矢量状态对喷管的推力系数、流量系数产生的影响都在3%以内。喷管的俯仰是通过同时转动上下扩张板来实现的,其与偏航作动相比表现出对性能更大的影响;另外发现在设计压比之前,气动俯仰角出现了随落压比先增大后减小的趋势,而设计压比之后渐渐趋于不变,基本和几何俯仰角相等,但落压比对气动偏航角却没有表现出太大的影响。

Abstract:

Numerical simulations were conducted on the 2-D convergent-divergent vector nozzles with spherical convergent flap to evaluate the static internal performance of vectored and unvectored nozzles.It was performed to analyze the effects of the geometric pitch and yaw vector angles on the discharge coefficient and resultant gross-thrust ratio,and the relationship between pressure ratios and the resultant thrust vector angle.All the nozzles have the same throat aspect ratio of 2.083.Results of the study indicate that the effect of geometric vector angles on Cv,and Cd was small(less than 3%).Because the pitch vectoring was accomplished by simultaneous deflection of the upper and lower divergent flaps,it caused lower resultant thrust ratio than the yaw vectoring did.A peak resultant vector angle which was larger than the geometric vector angle occurred at NPR below design,and the resultant vector angle was close to the geometric vector angle at NPR above design.But the resultant yaw thrust angles were nearly independent of NPR.