Page 163 - Analysis and Design of Energy Geostructures

Heat and mass transfers in the context of energy geostructures 135

i
k ρ g k g
i
k 5 f 5
μ f η f
i
2
where k [m ] is the intrinsic (or geometric) permeability, that is a por-
tion of the hydraulic conductivity and property of the porous material
2
only (not of the fluid), η [m /s] is the kinematic viscosity of the fluid
f
2
and g [m/s ] is the gravitational acceleration.
tt. Threshold values of groundwater flow velocities that may be
accounted for considering or neglecting convection in the ground
for analyses and designs of energy geostructures are in the range of
v rw 5 0:5 2 1 m/day.
uu. The mass conservation equation reads
@ρ

2 r ρv rf ;i 5
@t
3
where r represents the divergence operator, ρ [kg/m ] and v rf ;i [m/s]
are the bulk density and velocity of the fluid, while t is the time [s].
vv. No, it is not. The stored heat would be transferred away because of the
groundwater flow.
ww. Conduction.