Turbulence Modeling for Low-Reynolds-Number Flows

Characteristics of Turbulent Flow Past Passive Rectangular Cavity at Large Reynolds Numbers

“…The SST k-x turbulence model is a hybrid model, which combines the original k-e and k-x models. This model is widely used for flows with adverse pressure gradients and recirculating flows [12,14]. This model solves the turbulent kinetic energy equation and its specific dissipation rate as given in Eqs.…”

Low Reynolds Number Flows and Transition

“…Recently, Cutrone et al (2008) proposed to use a combination of the two conditions for ω in the case of separated flows. Catalano & Tognaccini (2010) conducted on a numerical study over SD 7003 aerofoil has Re=6x10 4 .I nt h is study, RANS and DNS approach were used. Menter's standart k-ω SST and k-ω SST-LR (Low Reynolds) model were used for RANS approach.…”

Validating the URANS shear stress transport γ −Reθ model for low‐Reynolds‐number external aerodynamics

“…Catalano and Tognaccini showed that using the SST model and imposing a transition point at 10% chord‐lengths downstream from the point of minimum friction coefficient results in improved LSB predictions. In this line of thought, Tang proved that running a baseline RANS laminar simulation, determining the transition point as the location where the tangential velocity at the wall reverses its direction for the second time after separation, and then performing another RANS simulation with a complete turbulence model activated only after the transition point produces similar results to LES and DNS.…”

“…Tang tested one of Abid's low‐Reynolds‐number k ‐ ϵ models on the Selig Donovan 7003 airfoil at a Reynolds number of 6.0 ×10 4 and found that it did predict the LSB, though the LSB was too long and too thick. Catalano and Tognaccini investigated a modified SST model (the SST‐LR), which included a parameter taking into account the magnitude of the Reynolds number, on the SD7003 airfoil at a Reynolds number of 6.0 ×10 4 . The SST‐LR with imposed transition proved superior to the traditional SST with imposed transition in predicting LSB characteristics.…”

“…lift, decreased stall angle, leading edge stall, increased drag, change in pitching moments, etc., depending on the airfoil [1,[6][7][8][9][10].In the field of CFD, several methods have been tested in an attempt to capture the LSB and the associated transition mechanisms, and to predict aerodynamic performances. DNS and LES methods have proven capable in predicting LSB dynamics and transition [11][12][13][14]. These methods remain, however, costly in terms of both user input and computational resources.The semiempirical approximate envelope (e N / method, which is based on linear stability theory, has also been successfully used to capture the complex phenomena associated with transitional turbulence, including the Tollmien-Schlichting (TS) and KH instabilities [12,[15][16][17].…”