Assuming a convection-diffusion problem where the velocity is in the negative direction (to the left side).
Using the upwind scheme:

Question

Assuming a convection-diffusion problem where the velocity is in the negative direction (to the left side).  Using the upwind scheme:

Answer

ϕ w = ϕ P   and   ϕ e = ϕ W {"version":"1.1","math":"\phi_w=\phi_P~ 	ext{and} ~\phi_e=\phi_W"}

Answer

ϕ w = ϕ E   and   ϕ e = ϕ P {"version":"1.1","math":"\phi_w=\phi_E~ 	ext{and} ~\phi_e=\phi_P"}

Answer

ϕ w = ϕ e = ϕ W {"version":"1.1","math":"\phi_w=\phi_e=\phi_W"}

Answer

ϕ w = ϕ P   and   ϕ e = ϕ E {"version":"1.1","math":"\phi_w=\phi_P~ 	ext{and} ~\phi_e=\phi_E"}

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