22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-P4.4

A NUMERICAL INVESTIGATION OF THE FLOWS IN AND AROUND ANNULAR-PLUG NOZZLE CONFIGURATIONS

D. A. Perigo, N.Qin
Cranfield University, UK

Keywords: plug nozzle, external expansion nozzle, numerical simulation, turbulence modelling

Recently there has been a resurgence of interest in the use of self adapting nozzles, specifically the External Expansion Nozzle (EEN), for space launch applications. This can be considered an effect of the renewed interest in single stage to orbit launch vehicle designs, notably the X33. This poster details the work to date at Cranfield, in conjunction with the European Space Agency, into the investigation the complex flowfields produced by such nozzles and assesses the applicability of modern computational techniques, in particular advanced two equation turbulence models, in the prediction of such flows. Results are presented for the simulation of the turbulent flow around an axisymmetric EEN geometry with external flow. Comparisons are made with experimental pressure measurements including pressures along the plug surface and pressures in the base region. Comparisons of velocity profiles against LDV measurements are also made. A grid sensitivity study is then performed for the Wilcox k??? model before moving on to compare against more advanced k??? formulations including cubic and quadratic nonlinear models. Finally, utilising our chosen turbulence models, the phenomenon of wake closure is investigated using two seperate methods and an asesment made of the suitability of the respective methods for the prediction of EEN flows.

view full paper