Page - 78 - in Intelligent Environments 2019 - Workshop Proceedings of the 15th International Conference on Intelligent Environments

2 j u i u d aC i F = , ( ) 3 2 j u d aC k F = , ε μ ρμ 2 k C T = j x i u ij k i x j u j x i u Tk P ∂ ∂ − ∂ ∂ + ∂ ∂ = ⎥ ⎦ ⎤ ⎢ ⎣ ⎡ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ δρμ 3 2 , ( ) i x q a M R v M R R i g T Sc T i x i g T T k G ∂ ∂ −+ ∂ ∂ = 00 Pr μθ θ μ 2.2. Numerical method The governing equations are compressible Reynolds-averaged Navier-Stokes equations for the conservation of mass, momentum, energy, turbulence kinetic energy (k), and dissipation rate of turbulence kinetic energy (ɛ). The CFD model is based on a standard k-ɛ model designated for the analysis of turbulent flows in aerodynamic engineering. This model has been modified by incorporating the effect of the Coriolis force on flow motions and adiabatic processes on air temperature variation. In addition to this the buoyancy effect due to water vapour is considered as a source of turbulence kinetic energy. The effects of potential temperature, Coriolis force and vapour buoyancy are newly introduced here into the governing equations in order to reproduce various physical dynamics at city-scale. The pressure term, which appears in an ordinary equation of energy transfer, is combined with that of potential temperature and expressed together in the equation of energy transfer as a potential term. The Semi Implicit Method for Pressure-Linked Equations Consistent (SIMPLEC) method is used to solve the pressure in the equation of motion in order to afford more numerical stability. The governing equations are discretised by the Finite Difference Method (FDM) on a Cartesian structured grid, which in this paper is regular horizontally and staggered vertically. Figure 1. Model description. M.Bakkali andY.Ashie /RANSModelling forLocalClimates,EnergyUseandComfortPredictions78