# A Critical Review of Supersonic Flow Control for High-Speed Applications
## 5 Critical Analysis of Literature
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Type of Object** & **Technique Adopted** & **Focused Parameter** & **Limitations** & **Reference** \\ \hline \multirow{4}{*}{Compression corner calculation model} & \multirow{4}{*}{ANSYS Fluent with k-\(\epsilon\) turbulence model} & Numerical investigations in the supersonic flow field with different injection pressure ratios, actuation positions, and nozzle types & The only simulation was used for investigation & [36] \\ \hline CD nozzle with sudden expansion duct & Experimental, CFD and DOE & Effect of microjet control in a sudden expansion duct with the parametric investigation & Numerical investigation done by 2D model and microjet location is fixed to a single point & [2] \\ \hline CD nozzle with sudden expansion duct & RSM, clustering, and random forest regression & Pressure in suddenly expanded high-speed aerodynamic flow & Predicting the pressure values using the optimization method with and without microjet controller & [166] \\ \hline Resonant high-speed cavity & Wind tunnel test with a blowdown-type facility & High-frequency pulsed supersonic microjets to control resonant high-speed cavity flows & The fact that the REM/ SmartREM actuator performance can be enhanced & [35] \\ \hline \multirow{4}{*}{Cylindrical cavity structure takes} & A computational method based on high-order numerical techniques & Flow physics of a pulsed microjet actuator for high-speed flow control & Efficient and geometrically complicated pulsed actuators were developed for various high-speed flow and noise control & [168] \\ \hline \multirow{4}{*}{Ultra-compact serpentine inlet} & Experimental work with high-pressure air supply and CFD & Microjet flow control in an ultra-compact serpentine inlet & Mach number of inlet throat between 0.2 to 0.5, and it is varied to a higher number & [169] \\ \hline \multirow{4}{*}{Crewless Arial Vehicle} & Experimental wind tunnel test & Microjet-based active flow control on a fixed-wing UAV & Experimental results possible to simulate with the CFD model & [170] \\ \hline \multirow{4}{*}{Impinging Jet} & Experimental work with supersonic jet facility & Control of impinging supersonic jet flows using microjets & A fluent model will be helpful in such an example & [171] \\ \hline \multirow{4}{*}{Supersonic Crossflow model} & Experimental work in a supersonic wind tunnel & Properties of resonance-enhanced microjets in supersonic crossflow & Limited to experimental work and also the Mach number can be varied & [172] \\ \hline \multirow{4}{*}{Ahmed body and NACA 0015 airfoil} & An experimental study was conducted in a subsonic wind tunnel & Active flow control by micro-blowing and effects on aerodynamic performances & Experimental work only & [173] \\ \hline \multirow{4}{*}{Flap’s pressure-side} & Experimental approach & Microjet configuration sensitivities for active flow control on multi-element high-lift systems & CFD and data optimization are helpful techniques to predict the multi-element high-lift system & [174] \\ \hline \multirow{4}{*}{Flap’s pressure-side} & Experimental approach & Surface-normal active flow control for lift enhancement and separation mitigation for high-lift standard research model & Other aerodynamic forces & [175] \\ \hline \multirow{4}{*}{Spaced jet configurations} & Experimental investigation & Control of compression-ramp-induced interaction with steady microjets. & It is advantageous to utilize a control design (MJ6) that functions well & [176] \\ \hline \multirow{2}{*}{Double-offset diffuser} & Experimental technique & Flow dynamics affected by active flow control in an offset diffuser & Parametric study to predict more accurate results from the experimental data & [177] \\ \hline \multirow{2}{*}{Series of cavity flow} & Experimental technique & The effects of high-frequency, supersonic microjet injection on a high-speed cavity flow & Specific Mach 1.5 & [178] \\ \hline \multirow{4}{*}{cylindrical cavity investigation} & Simulation and Experimental investigation & Simulations of pulsed actuators for high-speed flow control results & The parametric investigation will be effective in changing flow control results & [179] \\ \hline \hline \end{tabular}
\end{table}