TABLE 2.

Boundary conditions applied in the CFD simulation.

Location	Electrostatic model	Flow model	Thermal model	Transport equation
Inlet (1)	∇⁡Φ = 0	$u=2\cdot \frac{\stackrel{\_}{V}}{\mathrm{\pi }{R}^2}\cdot \left(1-{\left(\frac{r}{R}\right)}^2\right)$ v=0 w=0	T = T0	Fp = 0
Grounding (2)	U=0	uwall = 0	qwall = 0	∇⁡Fp = 0
Isolator (3)	∇⁡Φ = 0	uwall = 0	qwall = 0	∇⁡Fp = 0
High voltage electrode (4)	U = U0	uwall = 0	qwall = 0	∇⁡Fp = 0
Outlet (5)	∇⁡Φ = 0	pstat = pspec	∇⁡T = 0	∇⁡Fp = 0

The respective boundaries are indicated by the numbers in Figure 1.