ToolsProcessingModelsTurbulenceRASRSTMSpeziale, Sarkar and Gatski (SSG)On this pageSpeziale, Sarkar and Gatski (SSG)Properties Reynolds stress model Model equations DDt(ρϵ)=∇ ∙ (Dϵ∇ϵ)+Cϵ1ρGϵk−Cϵ2ρϵ2k+Sϵ \Ddt{\rho \epsilon} = \div \left( D_\epsilon \grad \epsilon \right) + C_{\epsilon 1} \rho G \frac{\epsilon}{k} - C_{\epsilon 2} \rho \frac{\epsilon^2}{k} + S_\epsilonDtD(ρϵ)=∇∙(Dϵ∇ϵ)+Cϵ1ρGkϵ−Cϵ2ρkϵ2+Sϵ DDt(ρR)=∇ ∙ (ρDR∇R)−(C12ϵ+C1∗2G)ρρkR+ρP−13I((2−C1)ϵ−C1∗G)ρ+C2ρϵdev(innerSqr(b))+ρk((C3−C3∗∣b∣)dev(S)+C4dev(twoSymm(b ∙ S))+C5twoSymm(b ∙ Ω)) \Ddt{\rho \tensor{R}} = \div \left( \rho D_{\tensor{R}} \grad \tensor{R} \right) - \left( \frac{C_1}{2}\epsilon + \frac{C_{1}^{*}}{2}G \right) \rho \frac{\rho}{k}\tensor{R} + \rho P - \frac{1}{3}\tensor{I} ((2 - C_1)\epsilon - C_{1}^{*} G) \rho + C_2 \rho \epsilon \mathrm{dev}(innerSqr(\tensor{b})) + \rho k \left( (C_3 - C_{3}^{*} \mag{\tensor{b}}) \mathrm{dev}(\tensor{S}) + C_4 \mathrm{dev}(twoSymm(\tensor{b} \dprod \tensor{S})) + C_5 twoSymm(\tensor{b} \dprod \tensor{\Omega}) \right)DtD(ρR)=∇∙(ρDR∇R)−(2C1ϵ+2C1∗G)ρkρR+ρP−31I((2−C1)ϵ−C1∗G)ρ+C2ρϵdev(innerSqr(b))+ρk((C3−C3∗∣b∣)dev(S)+C4dev(twoSymm(b∙S))+C5twoSymm(b∙Ω)) Default model coefficients Usage The model is specified using: RAS{ turbulence on; RASModel SSG;} Further information Source code: Foam::RASModels::SSG References: Base model: Speziale et al. 73 Generalized gradient diffusion model of Daly and Harlow 13