Cold Flow Measurements of Supersonic Low Aspect Ratio Jet-Surface Interactions

Baier, Florian; Karnam, Aatresh; Gutmark, Ephraim

doi:10.1007/s10494-019-00098-w

Cited by 8 publications

(7 citation statements)

References 62 publications

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“…The TKE on major axis matches quite well with experimental data. Length of potential core in LES is also predicted well compared with experimental data from reference [16], which is, x/De = 7. This indicates that LES has captured the necessary trends exhibited in the experiments.…”

Section: Validationmentioning

confidence: 55%

“…Experimental data for jet centerline velocity and TKE along lip lines are reported in references [15,16], which are based on PIV measurements conducted at University of Cincinnati's Gas Dynamics Propulsion Lab, and are used for validation. PIV is a non-intrusive measurement technique with minimal distortion to the flow, and therefore, is an obvious choice for the validation of results.…”

Section: Validationmentioning

confidence: 99%

“…QCR RANS overpredicts the TKE along minor-axis lip line, while it is adequate on major-axis lip line. The TKE in experimental data [16] is defined as = ( ′ ′ + 2 ′ ′ ), and therefore, this definition is used to plot the TKE in LES. The results are agreeable in quality and sufficient to move forward with the objective of the present study.…”

Section: Validationmentioning

confidence: 99%

“…The results are agreeable in quality and sufficient to move forward with the objective of the present study. ence [16], which is, x/De = 7. This indicates that LES has captured the necessary trends exhibited in the experiments.…”

Section: Validationmentioning

confidence: 99%

“…Meanwhile, Bellan [14] used the dynamic Smagorinsky model to achieve closure. Others [15,16] reported the experimental results on flow and noise characteristics of rectangular jets. Bridges and Wernet [17] experimentally investigated the turbulence statistics associated with rectangular jets at low to high aspect ratios, which provided some insights on crossflow turbulence.…”

Section: Introductionmentioning

confidence: 99%

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Improved Supersonic Turbulent Flow Characteristics Using Non-Linear Eddy Viscosity Relation in RANS and HPC-Enabled LES

et al. 2021

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A majority of the eddy viscosity models for supersonic turbulent flow are based on linear relationship between Reynolds stresses and mean strain rate. The validity of these models can be improved by introducing non-linearity in relation as RANS models offer advantages in terms of reduced turnaround times typical of industry applications. With these benefits, the present work utilizes quadratic constitutive relation (QCR) with Menter’s k omega SST model to characterize the flowfield of rectangular jets. The sensitivity of this model with QCR, weighted towards diffusion, dissipation, and a combination of both, is addressed. Viscous large eddy simulations (LES) with WALE subgrid scale models are employed for qualitative comparisons using a commercial solver. Massively parallel LES are enabled by the new in-house 1088-core computing cluster at the University of Cincinnati and are also used for benchmarking. The nearfield results are validated with available experimental data and show good agreement in both fidelities. Flow characteristics, including the shear layer profiles, Reynolds stresses, and turbulence kinetic energy (TKE) and its production are compared. LES reveal higher TKE production in the regions with highest Reynolds stresses. It is comparatively lower in QCR RANS. As a special case of TKE analysis in jets, a preliminary investigation of retropropulsion is outlined for rectangular nozzles for the first time. Improved flow behavior by implementation of a non-linear relationship between Reynolds stresses and mean strain rate is demonstrated.

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Section: Validationmentioning

confidence: 55%

Section: Validationmentioning

confidence: 99%

Section: Validationmentioning

confidence: 99%

Section: Validationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Improved Supersonic Turbulent Flow Characteristics Using Non-Linear Eddy Viscosity Relation in RANS and HPC-Enabled LES

et al. 2021

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Experimental analysis of an under-expanded jet interacting with a tangential flat plate: Flow visualizations and wall pressure statistics

Camussi

Ahmad

Meloni

et al. 2022

Experimental Thermal and Fluid Science

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Effect of tab parameters on the near-field mixing characteristics of a Mach 1.5 elliptic jet

2021

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The effect of delta-tabs with its apex leaning downstream on the jet mixing characteristics of a Mach 1.5 elliptic jet of aspect ratio (AR) 3.37 is reported in this paper. The delta-tabs were placed along the minor and major axes of the elliptic nozzle, referred to as tab configuration C1 and C2, respectively. For each tab configuration, four different orientation angles varying from θ= 90∘ to 150∘ were studied, where θ= 90∘ is the tab positioned normal to the nozzle exit and θ= 150∘ is the tab oriented in the downstream direction at the nozzle exit. The tab effects on jet manipulation were investigated via shadowgraph visualization, and the mean Pitot pressure was measured along the jet centerline and along the orthogonal planes of the jet. The non-dimensonalized supersonic core length Lc*, average shock-cell spacing Ls¯*, and the axis-switching location xas* were examined in detail to understand the jet characteristics of the natural and manipulated jets. The mixing capability of the manipulated jets quantified based on the reduction in supersonic core length ΔLc* depends strongly on the ideally expanded jet Mach number Mj, tab configuration (C1 and C2), and θ. As such, the ΔLc* for the manipulated jet at θ= 135∘ is the largest, revealing the optimal tab orientation for jet mixing enhancement, as also observed for the circular jet [Zaman et al., “Control of an axisymmetric jet using vortex generators,” Phys. Fluids 6(2), 778–793 (1994)]. The relationship between ΔLc* and ΔLs* is presented to understand the correlation between the jet mixing and noise characteristics of the manipulated jet. Discussion is conducted based on the dependence of ΔLc* and ΔLs* with θ, which provides useful insight into the jet flow physics. With suitable placement of tabs C1 and C2, the axis switching could be either stopped or augmented. The superior mixing characteristics of an elliptic jet relative to a circular jet, which were found in previous works on the supersonic over-expanded jet [Kumar and Rathakrishnan, “Characteristics of a supersonic elliptic jet,” Aeronaut. J. 120(1225), 495 (2016)] prevail in the supersonic jet under-expanded jet as well.

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Cold Flow Measurements of Supersonic Low Aspect Ratio Jet-Surface Interactions

Cited by 8 publications

References 62 publications

Improved Supersonic Turbulent Flow Characteristics Using Non-Linear Eddy Viscosity Relation in RANS and HPC-Enabled LES

Improved Supersonic Turbulent Flow Characteristics Using Non-Linear Eddy Viscosity Relation in RANS and HPC-Enabled LES

Experimental analysis of an under-expanded jet interacting with a tangential flat plate: Flow visualizations and wall pressure statistics

Effect of tab parameters on the near-field mixing characteristics of a Mach 1.5 elliptic jet

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