Comparison and Modification of Various Turbulence Models for Analysis of Fluid Microjet Injection into the Boundary Layer over a Flat Surface

Razzaghi, Mohammad Javad Pour; Masoumi, Yasin; Sani, Seyed Mojtaba Rezaei; Liu, Yue

doi:10.21203/rs.3.rs-2241386/v1

Cited by 5 publications

(1 citation statement)

References 9 publications

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“…This model is commonly used in aerodynamic problems and is very suitable for predicting pressure gradients within the boundary layer [22]. The y + corresponding to this model is very low (y + < 5), which allows it to accurately predict aerodynamic properties close to the boundary layer compared to 2-equation models such as k − , whose y + is higher (y + < 30) [44][45][46].…”

Section: Determination Of Aerodynamic Coefficients By Means Of Cfd 22...mentioning

confidence: 99%

Design and Determination of Aerodynamic Coefficients of a Tail-Sitter Aircraft by Means of CFD Numerical Simulation

et al. 2022

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Vertical take-off and landing (VTOL) aircraft have become important aerial vehicles for various sectors, such as security, health, and commercial sectors. These vehicles are capable of operating in different flight modes, allowing for the covering of most flight requirements in most environments. A tail-sitter aircraft is a type of VTOL vehicle that has the ability to take off and land vertically on it elevators (its tail) or on some rigid support element that extends behind the trailing edge. Most of the tail-sitter aircraft are designed with a fixed-wing adaptation rather than having their own design. The design of the tail-sitter carried out in this work had the particularity of not being an adaptation of a quad-rotor system in a commercial swept-wing aircraft, but, rather, was made from its own geometry in a twin-rotor configuration. The design was performed using ANSYS SpaceClaim CAD software, and a numerical analysis of the performance was carried out in ANSYS Fluent CFD software. The numerical results were satisfactorily validated with empirical correlations for the calculation of the polar curve, and the performance of the proposed tail-sitter was satisfactory compared to those found in the literature. The results of velocity and pressure contours were obtained for various angles of attack. The force and moment coefficients obtained showed trends similar to those reported in the literature.

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Section: Determination Of Aerodynamic Coefficients By Means Of Cfd 22...mentioning

confidence: 99%

Design and Determination of Aerodynamic Coefficients of a Tail-Sitter Aircraft by Means of CFD Numerical Simulation

et al. 2022

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Heritage building facades preservation: Automatic fresh air curtain wall generation for air pollutant dilution based on digital twins

Zhang,

Kwok,

Cheng

2024

Journal of Building Engineering

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Controlling flow separation over a curved ramp using vortex generator microjets

et al. 2022

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Introducing a fluid microjet into the boundary layer to increase fluid momentum and hence delay separation is a method for actively controlling a flow separation region. The present work numerically analyzed the control of a separation bubble behind a ramp. For this purpose, we first verified the steady-state numerical results for a flow (without a jet) over the ramp against reliable experimental studies from the literature. Next, the effects of introducing a microjet to the flow were also verified. A jet was then placed at three different distances above the ramp to study its impact on various parameters, including velocities, Reynolds stresses, pressure, vorticity, streamlines, and the separation bubble size. As the jet was moved further back, the jet-induced upwash region grew considerably. Finally, the effects of using three identical jets were studied and compared against those of a single jet. The results indicated that using a three-jet array shrank the separation bubble. Using an array with d/ D = 15 (distance between microjets over microjet diameter) can limit laterally the separation bubble about 2.75 times smaller than a single jet in the z-direction. Also, the employment of the jet managed to decrease the length of the separation zone in the x-direction up to 78%, in the case of Lx/ L1 = 0.0143 (longitudinal distance of microjet from above the ramp over ramp length) and d/ D = 10.

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Comparison and Modification of Various Turbulence Models for Analysis of Fluid Microjet Injection into the Boundary Layer over a Flat Surface

Cited by 5 publications

References 9 publications

Design and Determination of Aerodynamic Coefficients of a Tail-Sitter Aircraft by Means of CFD Numerical Simulation

Design and Determination of Aerodynamic Coefficients of a Tail-Sitter Aircraft by Means of CFD Numerical Simulation

Heritage building facades preservation: Automatic fresh air curtain wall generation for air pollutant dilution based on digital twins

Controlling flow separation over a curved ramp using vortex generator microjets

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