CAJ | 학술논문

RBCC发动机可多模态工作，能适应宽广的飞行包线，因而其火箭尾流剪切作用变化强烈、流道截面变化大，喷油规律复杂，给发动机建模与控制研究带来困难。针对RBCC发动机的地面直连实验构型，采用三维CFD计算分析RBCC流场特点，研究发动机状态变量特征，并基于CFD计算结合拟合法的建模思路，建立了RBCC状态空间模型，模型的计算结果与三维CFD的计算结果有较好的吻合度，均方差满足要求。研究表明，在一定范围内增加计算特征数据点个数，可提高建模精度，但当计算特征数据点的个数超过20时，继续增加点的个数对精度的提高非常有限。
RBCC발동궤가다모태공작，능괄응관엄적비행포선，인이기화전미류전절작용변화강렬、류도절면변화대，분유규률복잡，급발동궤건모여공제연구대래곤난。침대RBCC발동궤적지면직련실험구형，채용삼유CFD계산분석RBCC류장특점，연구발동궤상태변량특정，병기우CFD계산결합의합법적건모사로，건립료RBCC상태공간모형，모형적계산결과여삼유CFD적계산결과유교호적문합도，균방차만족요구。연구표명，재일정범위내증가계산특정수거점개수，가제고건모정도，단당계산특정수거점적개수초과20시，계속증가점적개수대정도적제고비상유한。
RBCC engine can operate at multi?modes( ( inject?,ramjet,scramjet and rocket as well) ) and adapt to a wide flight envelope,which is mainly resulted from the shearing action between the primary rocket plume and inlet air varies drastically. The cross?section along the flow path varies a lot for mounting the rocket,stabling the burning and accelerating the gases, and meanwhile the fuel is injected changing in both the amounts and the positions as well according to the operating mode. The complex driving?forces result in the difficulties to develop the performance model and to control RBCC.Based on the ground test configuration of RB?CC engine,the characteristics of flow field and state variables of RBCC engine were studied by using three?dimensional CFD,and then a state variable model with the method of CFD and linear fitting was developed.It is shown that the state variable model matches up with CFD calculations. Studies also show that modeling accuracy can be improved by increasing the data points till 20.