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Advances in Aircraft and Spacecraft Science Volume 10, Number 4, July 2023 , pages 303-315 DOI: https://doi.org/10.12989/aas.2023.10.4.303 |
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Numerical investigation of turbulence models with emphasis on turbulent intensity at low Reynolds number flows |
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Musavir Bashir, Parvathy Rajendran, Ambareen Khan, Vijayanandh Raja and Sher Afghan Khan
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| Abstract | ||
| The primary goal of this research is to investigate flow separation phenomena using various turbulence models. Also investigated are the effects of free-stream turbulence intensity on the flow over a NACA 0018 airfoil. The flow field around a NACA 0018 airfoil has been numerically simulated using RANS at Reynolds numbers ranging from 100,000 to 200,000 and angles of attack (AoA) ranging from 0o to 18o with various inflow conditions. A parametric study is conducted over a range of chord Reynolds numbers for free-stream turbulence intensities from 0.1 % to 0.5 % to understand the effects of each parameter on the suction side laminar separation bubble. The results showed that increasing the free-stream turbulence intensity reduces the length of the separation bubble formed over the suction side of the airfoil, as well as the flow prediction accuracy of each model. These models were used to compare the modeling accuracy and processing time improvements. The K- SST performs well in this simulation for estimating lift coefficients, with only small deviations at larger angles of attack. However, a stall was not predicted by the transition k-kl-omega. When predicting the location of flow reattachment over the airfoil, the transition k-klomega model also made some over-predictions. The Cp plots showed that the model generated results more in line with the experimental findings. | ||
| Key Words | ||
| CFD simulation; NACA 0018 airfoil; Reynolds number; turbulence model; turbulent intensity | ||
| Address | ||
| Musavir Bashir, Parvathy Rajendran, Ambareen Khan: School of Aerospace Engineering, Universiti Sains Malaysia, Engineering Campus, Nibong Tebal, Pulau Pinang, Malaysia Vijayanandh Raja: Department of Aeronautical Engineering, Kumaraguru College of Technology, Coimbatore-641049, Tamil Nadu, India Sher Afghan Khan: Department of Mechanical Engineering, Faculty of Engineering, International Islamic University, Kuala Lumpur 53100, Selangor, Malaysia | ||
