| Joint aperture at zero normal stress, \(u_{h0}\) | 
flowplane property aperture-initial | 
m | 
| Joint maximum aperture, \(u_{max}\) | 
flowplane property aperture-maximum | 
m | 
| Joint minimum (residual) aperture, \(u_{res}\) | 
flowplane property aperture-minimum | 
m | 
| Fluid bulk modulus, \(K_w\) | 
block fluid property bulk | 
Pa | 
| Fluid density, \(ρ_f\) | 
block fluid property density | 
kg/m3 | 
| Dynamic viscosity, \(μ\) | 
block fluid property viscosity | 
Pa · sec | 
| Flow rate or discharge per unit width of joint \(q\) | 
flowplane edge apply discharge | 
m3/sec · m | 
| Volumetric flow rate, \(Q\) | 
flowknot apply discharge | 
m3/sec | 
| Fluid pressure, \(p\) | 
flowpknot apply pore-pressure | 
Pa | 
| Joint hydraulic conductivity, \(k_H\) | 
  | 
m/s | 
| Gas flow constant, \(γ\) | 
block fluid gas alpha | 
  | 
| Gas flow constant, \(B\) | 
block fluid gas constant | 
s2/m2 | 
| Proppant volumetric concentration, \(c\) | 
flowplane vertex initialize proppant-volume | 
  | 
| Proppant grain diameter | 
block fluid proppant grain-size | 
m | 
| Proppant density, \(ρ_d\) | 
block fluid proppant density | 
kg/m3 | 
| Proppant pack intrinsic permeability | 
block fluid proppant permeability | 
M3 | 
| Matrix mobility coefficient, \(k\) | 
block zone fluid property permeability | 
m2/(Pa/s) | 
| Matrix porosity, \(n\) | 
block zone fluid property porosity | 
  |