Particle image velocimetry study of the impinging height effect on the overexpanded supersonic impinging free jet of Ma = 1.754. Part 2: detailed velocity distribution

Abstract

In this article, the flowfield of an overexpanded axisymmetric supersonic impinging jet with exit Mach number 1.754 is studied using particle image velocimetry. In particular, the influence of the impinging height on the detailed flowfield velocity distributions has been investigated. The velocity distribution precisely indicates where the Mach disk and the plate shock are generated. With the increasing impinging height, the plate shock position is found to move away from the impinging wall, until it reaches the maximum of 0.767D for the dimensionless impinging height of Z/D = 2.5. With a further increasing of the impinging height, the plate shock moves back to the impinging wall. Furthermore, the shape, position, as well as size of the stagnation bubble zone can also be deduced from the velocity distribution. According to the time-averaged flowfield result, the velocity coefficient of the radial wall jet is found to be as high as 0.8146, which is critical to the ground erosion problem in the application. It indicated that although the radial velocity appeared to be supersonic in the instantaneous result in Part I [Xu J, Lin C and Sha J. Particle image velocimetry study of the impinging height effect on the overexpanded supersonic impinging free jet of Ma = 1.754. Part I: global coherent structure. Proc IMechE, Part G: J Aerospace Engineering 2012; 226(1): 64–73.], it is high subsonic in the mean result in this part. This disagreement is due to the intrinsic highly unsteady nature of the flow under investigation. The vorticity isopleths demonstrate that the stagnation bubble and the recirculating flow are formed due to the impingement of the nozzle inner shear layer of the main jet.

Keywords

Particle image velocimetry overexpanded supersonic impinging jet shock wave shear layer stagnation bubble recirculation vortex wall jet

Get full access to this article

View all access options for this article.

References

Donaldson

Snedeker

. A study of free jet impingement. Part 1. Mean properties of free and impinging jets. J Fluid Mech 1971; 45: 281–319.

Donaldson

Snedeker

. A study of free jet impingement. Part 2. Free jet turbulent structure and impingement heat transfer. J Fluid Mech 1971; 45: 477–512.

Carling

Hunt

. The near wall jet of a normally impinging, uniform, axisymmetric, supersonic jet. J Fluid Mech 1974; 66: 159–176.

Lamont

Hunt

. The impingement of underexpanded axisymmetric jets on perpendicular and inclined flat plates. J Fluid Mech 1980; 100: 471–511.

Gubanova

Lunev

Plastinina

. The central breakaway zone with interaction between a supersonic underexpanded jet and a barrier. Fluid Dyn 1973; 6(1): 298–301.

Messersmith NL. Aeroacoustics of supersonic and sonic impinging jets. In: 33rd AIAA aerospace sciences meeting and exhibit, AIAA-95-509, Reno, NV, 9–12 January 1995.

Krothapalli

Rajakuperan

Alvi

. Flow field and noise characteristics of a supersonic impinging jet. J Fluid Mech 1999; 392: 155–181.

Alvi FS and Iyer KG. Mean and unsteady flowfield properties of supersonic impinging jets with lift plates. In: 5th AIAA/CEAS aeroacoustics conference and exhibit, AIAA-99-1829, Bellevue, WA, 10–12 May 1999.

Alvi

Shih

Elavarasan

Garg

. Control of supersonic impinging jet flows using supersonic micro jets. AIAA J 2003; 41(7): 1347–1355.

10.

Kumar

Lazic

Alvi

. Control of high-temperature supersonic impinging jets using microjets. AIAA J 2009; 47(12): 2800–2811.

11.

Pundir B and Dhanak M. Surface pressure fluctuations due to an impinging supersonic underexpanded jet. In: 48th AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition, AIAA-2010-0107, Orlando FL, 4–7 January 2010.

12.

Dauptain

Cuenot

Gicquel

LYM

. Large eddy simulation of stable supersonic jet impinging on flat plate. AIAA J 2010; 48(10): 2325–2338.

13.

Inman JA, Danehy PM, Nowak RJ, et al. The effect of impingement on transitional behavior in underexpanded jets, In: 47th AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition, AIAA-2009-0591, Orlando FL, 5–8 January 2009.

14.

Henderson

Bridges

Wernet

. An experimental study of the oscillatory flow structure of tone-producing supersonic impinging jets. J Fluid Mech 2005; 542: 115–137.

15.

Kim

Park

. Oscillatory behavior of supersonic impinging jet flows. Shock Waves 2005; 14(4): 259–272.

16.

Mizukaki

. Visualization and force measurement of high-temperature, supersonic impulse jet impinging on baffle plate. J Visual 2007; 10(2): 227–235.

17.

Crafton

Carter

Elliott

. The impingement of sonic and sub-sonic jets onto a flat plate at inclined angles. Exp Fluids 2006; 41(5): 699–710.

18.

Xu J, Lin C and Sha J. Particle image velocimetry study of the impinging height effect on the overexpanded supersonic impinging free jet of Ma = 1.754. Part 1: global coherent structure. Proc IMechE Part G: J Aerospace Engineering 2012; 226(1): 64–73.