Numerical Study of the Starting Process in a Supersonic Nozzle

2005 ◽  
Vol 21 (2) ◽  
pp. 374-378 ◽  
Author(s):  
A.-S. Mouronval ◽  
A. Hadjadj
Author(s):  
Rodrigo Fazioli Gastaldo ◽  
Julian Camilo Restrepo Lozano ◽  
Ricardo Galdino da SIlva ◽  
Reinaldo Marcondes Orselli ◽  
José Roberto Simões Moreira ◽  
...  

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sathish Kumar K ◽  
Naren Shankar R ◽  
Anusindhiya K ◽  
Senthil Kumar B.R

Purpose This study aims to present the numerical study on supersonic jet mixing characteristics of the co-flow jet by varying lip thickness (LT). The LT chosen for the study is 2 mm, 7.75 mm and 15 mm. Design/methodology/approach The primary nozzle is designed for delivering Mach 2.0 jet, whereas the secondary nozzle is designed for delivering Mach 1.6 jet. The Nozzle pressure ratio chosen for the study is 3 and 5. To study the mixing characteristics of the co-flow jet, total pressure and Mach number measurements were taken along and normal to the jet axis. To validate the numerical results, the numerical total pressure values were also compared with the experimental result and it is proven to have a good agreement. Findings The results exhibit that, the 2 mm lip is shear dominant. The 7.75 mm and 15 mm lip is wake dominant. The jet interaction along the jet axis was also studied using the contours of total pressure, Mach number, turbulent kinetic energy and density gradient. The radial Mach number contours at the various axial location of the jet was also studied. Practical implications The effect of varying LT in exhaust nozzle plays a vital role in supersonic turbofan aircraft. Originality/value Supersonic co-flowing jet mixing effectiveness by varying the LT between the primary supersonic nozzle and the secondary supersonic nozzle has not been analyzed in the past.


Author(s):  
E.I. Jassim

In the present study, a numerical simulation is conducted to predict the influence of convergent-divergent nozzle geometry and NPR on the skin friction and shockwave location. Various shapes of nozzles are numerically simulated using the Computational Fluid Dynamics code. The shock position is examined to demonstrate the impact of nozzle shape on its location. Skin friction is shown to be smoothly decreasing at the divergent part of the nozzle for all NPRs lower than 2.0. However, an inverse behavioural trend was observed at NPR equal to 2. This could be attributed to the fact that the large disturbance of fluid near the wall is the major factor behind such an oddity. The results also show that the shock position is reliant on the nozzle geometry at certain NPR.


2007 ◽  
Vol 111 (1115) ◽  
pp. 51-58 ◽  
Author(s):  
S. Saha ◽  
D. Chakraborty

Abstract The starting process in a supersonic nozzle is numerically simulated. The Navier Stokes equations, in axisymmetric form, are solved using a higher order spatial and temporal accurate scheme. Good comparisons between experimental and numerical values of various flow parameters form the basis of further analysis. The insight of the starting process in the nozzle, namely, the movement of primary and secondary shocks and contact discontinuity, has been obtained through analysis of various flow parameters. It has been observed that the inviscid phenomenon is more predominant in the flow development process. Parametric studies have been carried out to determine the effect of nozzle divergence angle on the starting process.


Author(s):  
Kexin Wu ◽  
Heuy Dong Kim

In recent decades, the fluidic thrust vector control technique is one of the core strategies to redirect various aerospace vehicles, such as modern launch rockets, supersonic aircraft, and guided missiles. The fundamental theory of the shock vector control is that the gas is injected into the supersonic part of a conventional convergent–divergent nozzle from the transverse to cause interactions between the shock waves and boundary layers. Then, the deflection of the primary jet can be easily realized by the induced oblique shock waves. It was evident that the shock vector control is a very simple, low weight, low cost, and quick vectoring response technique to gain high thrust vectoring performance. In the present work, computational fluid dynamics studies were performed at different control parameters in a three-dimensional rectangular supersonic nozzle with the slot injector. For the validation of the numerical methodology, computational results were compared with experimental data referred to the NASA Langley Research Center. The static pressure distributions along the upper and lower nozzle surfaces in the symmetry plane were matched with the test data excellently. Numerical simulations were based on the well-assessed shear stress transport k–ω turbulence model. Second-order accuracy was selected to reveal more details of the flow-field as much as possible. Lots of factors were investigated, such as the momentum flux ratio, length-to-width ratio, injection location, and injection angle. The performance variations for different affecting factors were illustrated and some constructive conclusions were obtained to provide the reference for further investigations in fluidic thrust vector control field.


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