Why BC_Sym_Plane in turb solvers do nothing, no flux across the boundary should be done.

[ShiheJia]

I found that BC_Sym_Plane do nothing for turb solvers. For scalar vars, the symmetry BC is different from the euler BC that only works on the normal gradient of the velocity. Maybe BC_Sym_Plane should take the form of CTransLMSolver::BC_HeatFlux_Wall, because the boundary conditions of the Langtry-Menter model is a symmetry condition.

'''
inline void BC_Sym_Plane(CGeometry* geometry, CSolver** solver_container, CNumerics* conv_numerics,
CNumerics* visc_numerics, CConfig* config, unsigned short val_marker) override {
/--- Convective and viscous fluxes across symmetry plane are equal to zero. ---/
}
'''

'''
void CTransLMSolver::BC_HeatFlux_Wall(CGeometry *geometry, CSolver **solver_container, CNumerics *conv_numerics,
CNumerics *visc_numerics, CConfig *config, unsigned short val_marker) {
...
}
'''