Numerical Study of Characteristics of Underexpanded Supersonic Jet

Murugesan, Priyadharshini; Kumar, Arjun Biju; Kambhampati, Akhil Teja; Pillai, Shashank; Chandrasekar, Girish Chandar; Raghavannambiar, Srikrishnan Ambattu; Velamati, Ratna Kishore

doi:10.5028/jatm.v12.1126

Cited by 3 publications

(2 citation statements)

References 27 publications

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“…Second-order upwind schemes were used for solving the governing equations. The use of the solver for modeling supersonic flows with diverse applications has been reported in several previous studies, including [ 33 ] and [ 34 ].…”

Section: Computational Methodologymentioning

confidence: 99%

Enhancement of Film Cooling Effectiveness in a Supersonic Nozzle

Somasekharan

Srikrishnan

Kumar

et al. 2023

Entropy

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Film cooling as applied to rocket nozzles is analyzed numerically with emphasis on the assessment of the effect of the mixing of coolant with the hot stream. Cooling performance, as characterized by cooling effectiveness, is studied for three different coolants in the three-dimensional, turbulent flow field of a supersonic convergent-divergent nozzle operating with a hot stream temperature of 2500 K over a range of blowing ratios. The coolant stream is injected tangentially into the mainstream using a diffuser-type injector. Parameters influencing the effectiveness, such as coolant injector configuration and mixing layer, are analyzed. Thermal and species mixing between the coolant and the mainstream are investigated with regard to their impact on cooling effectiveness. The results obtained provide insight into the film cooling performance of the gases and the heat transfer characteristics associated with these three gases. An injector taper angle of 30° results in the most effective cooling among the configurations considered (0°, 15°, 30° and 45°). Mixing of the coolant with the hot stream is examined based on the distributions of velocity, temperature and species. The higher values of cooling effectiveness for Helium are attributed to its thermophysical properties and the reduced rate of mixing with the hot stream. The results further indicate that through optimization of the blowing ratio and the coolant injector configuration, the film cooling effectiveness can be substantially improved.

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Section: Computational Methodologymentioning

confidence: 99%

Enhancement of Film Cooling Effectiveness in a Supersonic Nozzle

Somasekharan

Srikrishnan

Kumar

et al. 2023

Entropy

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“…Numerical studies find extensive applications in the analysis of high velocity jets across a wide spectrum of applications [13,14]. Numerical simulations of compressible, turbulent jets using the Shear Stress Transport (SST) k-ω model were carried out for baseline nozzle and chevron nozzles with six lobes for three different penetration angles by Tide and Babu [15].…”

Section: Introductionmentioning

confidence: 99%

Acoustic Modeling of Compressible Jet from Chevron Nozzle: A Comparison of URANS, LES and DES Models

et al. 2022

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Chevron nozzles, which are characterized by the serrations at the nozzle exit, are widely used for suppressing jet noise in aircraft engines. The noise suppression is accomplished by the enhanced mixing of the exhaust streams, which, in turn, is a result of the streamwise vorticity induced by the serrations. The present study focuses on the numerical modeling of the acoustic field in a compressible jet issuing from a chevron nozzle at a Mach number of 0.8. The study evaluates the effectiveness of turbulence modeling approaches of Large Eddy Simulation and Detached Eddy Simulation methods and compares them with the less computationally intensive Unsteady Reynolds Averaged Navier–Stokes (URANS) formulation. The Ffowcs Williams–Hawkings noise model was used to predict the overall sound pressure level in the far field. The LES predictions of the acoustic signature were found to match well with the experimental data, whereas the URANS model grossly underpredicted the sound pressure levels in the compressible jet flow field.

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