Prompt Detail:
I want you to rewrite the code below so that it determines the velocity and the gas flow rate of the gas core associated with a particular percentage of hydrate growth and blockage. The code has to calculate the velocity of the gas and the back-pressure associate to every addition of 0.001% addition of gas hydrate growth, and store the data of each velocity of the gas core and back-pressure corresponding to a 0.001% increment of gas hydrate growth. Please stop the calculations when the gas hydrate velocity will be 0.
Here are the formulas:
The efficient tubing diameter:
R_eff=R(1- α_H )
Shen et al. (2018) correlation of flow behavior and consistency index:
n=0.99268-〖1.98 ϕ〗_H
m=0.04199 exp(56.40 ϕ_H^2 -2.582 ϕ_H)
average slurry thickness
δ_avr=Rα_sl
α_sl=0.01
the radius of the gas core
R_g=R_eff-δ_avr
The gas core density is as follows:
ρ_c=ρ_g ε_cr+ρ_sl (1-ε_cr )
The density of the slurry is as follows:
ρ_sl=100/(ϕ_H/ρ_h +(100-ϕ_H)/ρ_l )
ρ_sl=ρ_h ϕ_H+ρ_l (1-ϕ_H )
The gas core viscosity is as follows:
μ_c=μ_g ε_cr+μ_l (1-ε_cr )
We adopt Ling (2012) model to compute the gas core viscosity as follows:
μ_g=Ca×〖10〗^(-3) exp[X((〖6.24×10〗^(-2) ρ_g)/(62.4))^Y ]
Ca=(〖10〗^(-4) (9.18999+3.0893 (1000M_g )) 〖T(R)〗^(1.2288))/(208.99+18.83922 (1000M_g )+T(R) )
X=3.56014+((1000.01)/(T(R)))+0.124465 (〖1000M〗_g )
Y=2.47862-0.12294 X
For calculations consistencies, we adopt the Brill and Beggs (1978) viscosity model for computation of the water phase viscosity, which is as follows:
μ_w=exp[1.003-1.479×〖10〗^(-2) T+ 1.982×〖10〗^(-5) T^2 ]
For computations consistencies, the gas-water interfacial friction factor developed by Fore et al. (2000) is adopted and expressed for the case of average and non-average hydrate slurry thickness
f_w=0.005{1+300[(1+17500/R_eG ) 〖δ_cr〗_avr/2R-0.0015]}
f_w=0.005{1+300[(1+17500/R_eG ) (δ_cr (α,β))/2R-0.0015]}
Moreover, the gas-hydrate interfacial friction factor developed by Shi et al. (2018)
f_h=K(u) ρ_h/ρ_lb [(φ_h+φ_w^' ) (d_p/d_o )^(3-f_r ) ] (d_p/D)^2
φ_w^'=(m_w-n_g NM_w)/(ρ_w V_Total )
K(u)=(23.59e^(-u⁄(0.158))+1.028)×〖10〗^4
Therefore, the interfacial friction factor is as follows:
f_i=f_w+f_h
Thus, the velocity of the gas core associated with a particular percentage of hydrate growth and blockage could be expressed as follows
v_g=(n/(n-1)) (1/2m (-dP/dz+ρ_sl g sinα ))^(1/n) [R_g^((n-1)/n) R_eff^(2/n) (_2^1)F (-1/n,(n-1)/2n;3/2-1/2n;(R_g^2)/(R_eff^2 ))- R_eff^((n+1)/n) (_2^1)F (-1/n,(n-1)/2n;3/2-1/2n;1)]
With:
(_2^1)F (-1/n,(n-1)/2n;3/2-1/2n;1) and (_2^1)F (-1/n,(n-1)/2n;3/2-1/2n;(R_g^2)/R^2 ) The hypergeometric FUNCTION
(_2^1)F (-1/n,(n-1)/2n;3/2-1/2n;(R_g^2)/(R_eff^2 ))= 1-((n-1)/n)((R_g^2)/(R_eff^2 ))[(1/(3n-1))+((n-1)/(2n(5n-1)))((R_g^2)/(R_eff^2 ))]
(_2^1)F (-1/n,(n-1)/2n;3/2-1/2n;1)= 1-((n-1)/n)[(1/(3n-1))+((n-1)/2n)(1/(5n-1))]
the gas flow rate
Q_g=2.5×〖10〗^8 ((APv_g)/ZT)
The determination of the back-pressure is performed with the Schellhardt and Rawlins (1936) correlation by adopting Darcy’s flow.
By assuming a laminar flow and low flow rate, and low-pressure conditions, the expression of the back-pressure could be expressed as follows:
p_r^2-p_wf^2=Q_g/C
C=(0.703kh)/(Tμ_g Z[ln(r_e/r_w )-0.75+s] )
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