CAJ | 학술논문

为研究底部冷排气的圆柱体模型的底部压力和尾部流场特性，采用有限体积法编程求解二维轴对称 Navier-Stokes方程，对来流马赫数为2.47的底部排气圆柱体模型尾部流场进行数值模拟，并与实验进行对比。模型底部压力和尾部轴向速度场随排气参数的变化规律和实验吻合。分析了底排尾部流场中大、小回流区随排气参数的变化情况，以及底排气体出喷口后的流动规律。结果表明：在小排气参数时，底排气体出喷口后立即转向进入剪切层，底压迅速增加；随着排气参数增大，在喷口和底部拐角之间出现小的环状回流区，并不断增大，使底压增长率减小。研究结果可为进一步提高底排增压减阻效率提供参考。
위연구저부랭배기적원주체모형적저부압력화미부류장특성，채용유한체적법편정구해이유축대칭 Navier-Stokes방정，대래류마혁수위2.47적저부배기원주체모형미부류장진행수치모의，병여실험진행대비。모형저부압력화미부축향속도장수배기삼수적변화규률화실험문합。분석료저배미부류장중대、소회류구수배기삼수적변화정황，이급저배기체출분구후적류동규률。결과표명：재소배기삼수시，저배기체출분구후립즉전향진입전절층，저압신속증가；수착배기삼수증대，재분구화저부괴각지간출현소적배상회류구，병불단증대，사저압증장솔감소。연구결과가위진일보제고저배증압감조효솔제공삼고。
To study the characteristics of base flows for a cylindrical model with cold base bleed,two-dimensional axisymmetric Navier-Stokes equations were solved by using a finite volume scheme.Base flow-field of the model with mass bleed in a freestream of Mach 2.47 was simulated.The regularities of base pressure and axial velocity field varying with bleed parameters accord with experimental data.The size of primary recirculation and secondary recirculation near the base annulus was observed,and the flow law of base bleed gases outside the nozzle was investigated.The results show that at low bleed rates,base bleed gases turn around immediately after ej ecting from the nozzle,and then flow into the shear layer rapidly,and the base pressures increase.With the increase of bleed rates,the small annular circum fluence-area appears between nozzle and base corner,and the area keeps increasing,and the rise rate of base pressure decreases. The results offer reference for further improving the pressurization and dragreduction efficiency of base bleed.