Contents


Planewall_Q

 

 

The function planewall_Q(time, T_i, T_f, alpha, k, h, L) returns the heat transfer per unit area ([J/m^2 or Btu/ft^2]) for a bounded plane wall exposed to convection at one surface (x=L) and adiabatic at the other surface (x=0)

 

Inputs:

time - time relative to beginning of convection [sec]

T_i - initial temperature of plane wall [C], [K], [F], or [R]

T_f - bulk fluid temperature [C], [K], [F], or [R]

alpha - thermal diffusivity [m^2/s] or [ft^2/hr]

k - thermal conductivity of plane wall [W/m-K] or [Btu/hr-ft-R]

h - heat transfer coefficient [W/m^2-K] or [Btu/hr-ft^2-R]

L -  thickness of plane wall [m] or [ft]

 

Notes: 

Function planewall determines the Biot and Fourier numbers and calls the function planewall_Q_ND, which determines the non-dimensional heat transfer, Q_hat. Q_hat is then multiplied by the maximum heat transfer to obtain planewall_Q, as explained in section 3.5.2 of Nellis and Klein.

 

Example:

$UnitSystem SI K Pa J

time=5000 [sec]

T_i=303 [K]

T_f=363 [K]

alpha=8.608e-5 [m^2/s]

k= 233 [W/m-K]

h= 50 [W/m^2-K]

L= 0.5 [m]

Q=planewall_Q(time, T_i, T_f, alpha, k, h, L)

 

{Solution: q``=1.328E+07 [J/m^2]}

 

 

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