Modelling of Suddenly Expanded Flow Process in Supersonic Mach Regime using Design of Experiments and Response Surface Methodology

Document Type : Research Paper

Authors

1 Department of Mechanical Engineering, Birla Institute of Technology, RAK campus, Ras-Al-Khaimah, UAE

2 Department of Mechanical Engineering, International Islamic University Malaysia (IIUM), Kuala Lampur, Malaysia

3 Department of Mechanical Engineering, Bearys Institute of Technology, Mangalore, India

Abstract

The present work is an attempt to model, analyze, and control the flow at the base of an abruptly expanded circular duct by using design of experiments (DOE) and response surface methodology (RSM). Tiny-jets in the form of orifice were positioned at an interval of 900, 6.5 mm from the primary axis of the main jet of the nozzle. Experiments were conducted to measure two responses namely, base pressure without the use of micro jets or active control (WoC) and base pressure with the use of micro jets or active control (WC). Mach number (M), nozzle pressure ratio (NPR), area ratio (AR) and length to diameter ratio (L/D) were considered as input variables (parameters), which control the outputs (i.e. base pressure). Non-linear regression models based on central composite design (CCD) and Box-Behnken design (BBD) have been developed in order to facilitate the input-output relationships. Moreover, the significance of main, square and interaction terms of the developed models have been tested by performing analysis of variance (ANOVA). The ANOVA and significance test results and their respective correlation coefficient values indicate that both the CCD and BBD regression models are statistically adequate for both the base pressure responses of without control and with control respectively. The performances of the nonlinear models have been validated for accuracy prediction by use of 15 test cases. The performance of BBD model is found to be better in forecasting base pressure for both cases of without control and with control when compared to the CCD model.

Keywords

Main Subjects

[1]           R. Bansal, R. Sharma, Drag reduction of passenger car using add-on devices, Journal of Aerodynamics, Vol. 2014, 2014.
[2]           R. S. Wick, The effect of boundary layer on sonic flow through an abrupt cross-sectional area change, Journal of the Aeronautical Sciences, Vol. 20, No. 10, pp. 675-682, 1953.
[3]           H. H. Korst, A theory for base pressures in transonic and supersonic flow, J. appl. Mech., Vol. 23, pp. 593-600, 1956.
[4]           E. Rathakrishnan, Effect of ribs on suddenly expanded flows, AIAA journal, Vol. 39, No. 7, pp. 1402-1404, 2001.
[5]           E. Rathakrishnan, A. Sreekanth, Flows in pipes with sudden enlargement, in Proceeding of, 491-496.
[6]           P. Viswanath, S. Patil, Effectiveness of passive devices for axisymmetric base drag reduction at Mach 2, Journal of Spacecraft and Rockets, Vol. 27, No. 3, pp. 234-237, 1990.
[7]           S. A. Khan, E. Rathakrishnan, Active control of suddenly expanded flows from overexpanded nozzles, International Journal of Turbo and Jet Engines, Vol. 19, No. 1-2, pp. 119-126, 2002.
[8]           S. A. Khan, E. Rathakrishnan, Control of suddenly expanded flows with micro-jets, International journal of Turbo and Jet engines, Vol. 20, No. 1, pp. 63-82, 2003.
[9]           S. A. Khan, E. Rathakrishnan, Control of Suddenly Expanded Flows from Correctly Expanded Nozzles, International Journal of Turbo and Jet Engines, Vol. 21, No. 4, pp. 255-278, 2004.
[10]         S. A. Khan, E. Rathakrishnan, Active Control of Suddenly Expanded Flows from Underexpanded Nozzles, International Journal of Turbo and Jet Engines, Vol. 21, No. 4, pp. 233-254, 2004.
[11]         S. A. Khan, E. Rathakrishnan, Control of suddenly expanded flow, Aircraft Engineering and Aerospace Technology, Vol. 78, No. 4, pp. 293-309, 2006.
[12]         M. Badrinarayanan, An experimental investigation of base flows at supersonic speeds, The Aeronautical Journal, Vol. 65, No. 607, pp. 475-482, 1961.
[13]         M. A. A. Baig, F. Al-Mufadi, S. A. Khan, E. Rathakrishnan, Control of base flows with micro jets, International Journal of Turbo and Jet Engines, Vol. 28, No. 1, pp. 59-69, 2011.
[14]         M. Patel GC, P. Krishna, M. Parappagoudar, Modelling of squeeze casting process using design of experiments and response surface methodology, International Journal of Cast Metals Research, Vol. 28, No. 3, pp. 167-180, 2015.
[15]         M. Patel G.C, P. Krishna, M. B. Parappagoudar, Squeeze casting process modeling by a conventional statistical regression analysis approach, Applied Mathematical Modelling, Vol. 40, No. 15, pp. 6869-6888, 2016/08/01/, 2016.
[16]      B. J. Cantwell, Fundamentals of Compressible Flow, AA210, Department of Aeronautics and    Astronautics, Stanford University, California, USA, 1996.
[17]         M. Rouméas, P. Gilliéron, A. Kourta, Drag reduction by flow separation control on a car after body, International journal for numerical methods in fluids, Vol. 60, No. 11, pp. 1222-1240, 2009.
[18]       B. M. Genick , 2007, Gas Dynamics Tables, Version 1.3, 2007.
[19]         S. Rehman, S. Khan, Control of base pressure with micro-jets: part I, Aircraft Engineering and Aerospace Technology, Vol. 80, No. 2, pp. 158-164, 2008.
[20]         S. Ashfaq, S. A. Khan, E. Rathakrishnan, Control of Base Pressure with Micro Jets for Area Ratio 2.4, International Review of Mechanical Engineering (IREME), Vol. 8, No. 1, pp. 1-10, 2014.
[21]         N. K. Singh, E. Rathakrishnan, Sonic jet control with tabs, International Journal of Turbo and Jet Engines, Vol. 19, No. 1-2, pp. 107-118, 2002.
[22]         İ. Dağtekin, M. Ünsal, Numerical analysis of axisymmetric and planar sudden expansion flows for laminar regime, International journal for numerical methods in fluids, Vol. 65, No. 9, pp. 1133-1144, 2011.
[23]         J. D. Quadros, S. Khan, A. Antony, Predictive modeling of suddenly expanded flow process in the Supersonic Mach number regime using response surface methodology, 2017.
[24]         G. Layek, C. Midya, S. Mukhopadhyay, Effects of suction and blowing on flow separation in a symmetric sudden expanded channel, Nonlinear Anal Model, Vol. 13, pp. 451-465, 2008.
[25]         D. Drikakis, Bifurcation phenomena in incompressible sudden expansion flows, Physics of Fluids, Vol. 9, No. 1, pp. 76-87, 1997. 
Volume 49, Issue 1
June 2018
Pages 149-160
  • Receive Date: 16 December 2017
  • Revise Date: 08 January 2018
  • Accept Date: 14 January 2018