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Motivation



One of the key challenges in Pipe Flow Dynamics is to predict the along-hole temperature distribution during the stationary fluid transport.

In many practical cases the temperature distribution for the stationary fluid flow can be approximated by homogenous fluid flow model.

Pipeline Flow Temperature Model is addressing this problem with account of the varying pipeline trajectory, pipeline schematic and heat transfer with the matter around pipeline.


Inputs & Outputs


InputsOutputs

pipeline trajectory {\bf r} = {\bf r}(l) = \{ x(l), \, y(l), \, z(l) \}

along-pipe temperature T(t, l) distribution and evolution in time

pipeline cross-section area  A(l)


fluid density \rho(T, p) and fluid viscosity  \mu(T, p)


inflow temperature  T_0(t), inflow pressure  p_0, inflow rate  q_0


initial temperature   T_{e0}(l) of the medium around the pipeline


specific heat capacity c_p(l)thermal conductivity  \lambda_e(l)  of the medium around pipeline


heat transfer coefficient  U(l) based on pipeline schematic



Assumptions




Equations



(1) \rho \, c \, \frac{\partial T}{\partial t} = \frac{d}{dl} \, \bigg( \lambda \, \frac{dT}{dl} \bigg) - \rho \, c \, v \, \frac{dT}{dl}
(2) \rho_e \, c_e \, \frac{\partial T_e}{\partial t} = \nabla ( \lambda_e \nabla T_e)
(3) T(t=0, l) = T_{e0}(l)
(4) T_e(t=0, l, r) = T_{e0}(l)
(5) T(t, l=0) = T_0(t)
(6) T_e(t, l, r \rightarrow \infty) = T_{e0}(l)
(7) 2 \pi \, \lambda_e \, r_w \, \frac{\partial T_e}{\partial r} \, \bigg|_{r=r_w} = 2 \pi \, r_f \, U \, \bigg( T_e \, \bigg|_{r=r_w} - T \bigg)




(see Derivation of Stationary Isothermal Homogenous Pipe Flow Pressure Profile @model )

Approximations






References



https://en.wikipedia.org/wiki/Darcy_friction_factor_formulae

https://neutrium.net/fluid_flow/pressure-loss-in-pipe/ 







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