Flow structure of underexpanded elliptic jet
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摘要: 为了探讨超声速欠膨胀椭圆射流的流动特征,采用大涡模拟(LES)方法与高精度混合格式对出口压力比N分别为14、24、40的欠膨胀椭圆射流流场结构进行数值模拟。结果清晰描述了欠膨胀椭圆射流的三维(3D)结构特征与发展规律,并分析了因喷嘴方位曲率不一致而导致长轴与短轴平面上激波结构出现差异的原因。另外,结果还发现:当N为24时,短轴平面上射流域内的激波结构已由正规反射转变为马赫反射,但长轴平面上仍维持正规反射,而当N为40时,长轴与短轴平面上的激波结构均为马赫反射结构,由此可知喷嘴方位曲率变化越平缓,马赫反射形成所需的出口压力比越大。Abstract: To reveal the flow characteristics of a supersonic underexpanded elliptic jet, the flow structures of underexpanded elliptic jets at the nozzle pressure ratio N of 14, 24 and 40 were simulated using largeeddy simulation (LES) in combination with the high order hybrid schemes. The threedimensional (3D) flow characteristics and the evolution of underexpanded elliptic jet were illustrated from the results, and the reason for the different shock structures of the minor and major axis planes introduced by nonuniform curvature of the nozzle was discussed. Moreover, the results also found that the Mach shock reflection happened on the minor axis plane at N being 24, but regularreflection remained on the major axis plane. The shock structure of both major and minor axis planes were transferred into Mach reflection when N was 40. Therefore, the nozzle pressure ratio introducing the Mach shock reflection increases as the nozzle curvature radius becomes gentle.
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Key words:
- underexpanded jet /
- elliptical jet /
- shock wave /
- Mach shock reflection /
- largeeddy simulation
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[1] GUTMARK E J,GRINSTEIN F F.Flow control with noncircular jets[J].Annual Review of Fluid Mechanics,1999,31:239-272. [2] 张焕好,陈志华,姜孝海.亚声速等膨胀方管射流轴置换现象的数值研究[J].推进技术,2016,37(2):218-226.ZHANG Huanhao,CHEN Zhihua,JIANG Xiaohai.Numerical investigation on axisswitching of an isoexpanded subsonic square jet[J].Journal of Aerospace Power,2016,37(2):218-226.(in Chinese) [3] GRINSTEIN F F,GUTMARK E,PARR T.Near field dynamics of subsonic free square jets.A computational and experimental study[J].Physics of Fluids,1995,7(6):1483-1497. [4] XU M Y,ZHANG J P,MI J C,et al.Mean and fluctuating velocity fields of a diamond turbulent jet[J].Chinese Physics B,2013,22(3):034701.1-034701.8. [5] QUINN W R.Experimental study of the near field and transition region of a free jet issuing from a sharpedged elliptic orifice plate[J].European Journal of Mechanics B/Fluids,2007,26(4):583-614. [6] HO C M,GURMARK E.Vortex induction and mass entrainment in a small aspect ratio elliptic jet[J].Journal of Fluid Mechanics,1987,179:383-405. [7] HUSAIN H S,HUSSAIN A K M F.Elliptic jets:Part 1 characteristics of unexcited and excited jets[J].Journal of Fluid Mechanics,1989,208:257-320. [8] KWEON Y H,MIYAZATO Y,AOKI T,et al.Experimental investigation of nozzle exit reflector effect on supersonic jet[J].Shock Waves,2006,15(3/4):229-239. [9] MENON N,SKEWS B W.Rectangular underexpanded gas jets:effect of pressure ratio,aspect ratio and Mach number[R].AIAA 91-0996,1991. [10] TESHIMA K.Twodimensional focusing of a supersonic free jet by a rectangular orifice[J].Physics of Fluids,1987,30(7):1899-1901. [11] TESHIMA K.Threedimensional characteristics of supersonic jets[R].Weinheim,Germany:17th International Symposium on Rarefied Gas Dynamics,1990. [12] TSUTSUMI S,TERAMOTO S,YAMAGUCHI K,et al.Structure of underexpanded jets from square nozzles[J].AIAA Journal,2006,44(6):1287-1291. [13] KROTHAPALLI A,HSIA Y,BAGANOFF D,et al.On the structure of an underexpanded rectangular jet[R].NASA CR-169734,1982. [14] SCHADOW K C,GUTMARK E,KOSHIGOE S,et al.Combustion related shear flow dynamics in elliptic supersonic jets[J].AIAA Journal,1989,27(10):1347-1353. [15] ZHANG Huanhao,CHEN Zhihua,JIANG Xiaohai,et al.The starting flow structure and evolution of a planar supersonic jet[J].Computers and Fluids,2015,114:98-109. [16] ZHANG Huanhao,CHEN Zhihua,LI Baoming,et al.The secondary vortex rings of a supersonic underexpanded circular jet with low pressure ratio[J].European Journal of Mechanics B:Fluids,2014,46(7):172-180. [17] LOMBARDINI M,HILL D J,PULLIN D I,et al.Atwood ratio dependence of RichtmyerMeshkov flows under reshock conditions using largeeddy simulations[J].Journal of Fluid Mechanics,2011,670(3):439-480. [18] LUNDGREN T S.Strained spiral vortex model for turbulent fine structure[J].Physics of Fluids,1982,25:2193-2203. [19] HILL D J,PULLIN D I.Hybrid tuned centerdifferenceweno method for large eddy simulations in the presence of strong shocks[J].Journal of Computational Physics,2004,194(2):435-450. [20] PANTANO C,DEITERDING R,HILL D J.A low numerical dissipation patch based adaptive mesh refinement method for largeeddy simulation of compressible flows[J].Journal of Computational Physics,2007,221(1):63-87. [21] 张焕好,陈志华,姜孝海,等.强欠膨胀圆管射流中二次涡环的形成机理[J].推进技术,2015,36(8):1157-1163.ZHANG Huanhao,CHEN Zhihua,JIANG Xiaohai,et al.The generation mechanisms of secondary vortex rings of highly underexpanded circular jets[J].Journal of Propulsion Technology,2015,36(8):1157-1163.(in Chinese) [22] ZAREBEHTASH H,KONTIS K,GONGORAOROZCO N,et al.Compressible vortex loops:effect of nozzle geometry[J].International Journal of Heat and Fluid Flow,2009,30(3):561-576. [23] 张焕好,陈志华,姜孝海.二维喷管的初始流动[J].航空动力学报,2015,30(9):2174-2180.ZHANG Huanhao,CHEN Zhihua,JIANG Xiaohai.Initial flow of 2D planer nozzle[J].Journal of Aerospace Power,2015,30(9):2174-2180.(in Chinese)
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