Difference between revisions of "Gray correlation"

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(Workflow \varepsilon')
(Workflow \varepsilon')
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:<math> H_g = \frac{1-e^A}{R+1}</math>
 
:<math> H_g = \frac{1-e^A}{R+1}</math>
  
== Workflow <math>\varepsilon'</math> ==
+
== Workflow &epsilon;<sup>'</sup> ==
 
 
&epsilon;
 
  
 
== Nomenclature  ==
 
== Nomenclature  ==

Revision as of 18:33, 4 April 2017

Brief

  • The boundary between the bubble and slug flow[1]

Math & Physics

Following the law of conservation of energy the basic steady state flow equation is:

 144 \frac{\Delta p}{\Delta h} =  \bar \rho_m + \rho_m \frac{f v_m^2 }{2 g_c D} + \rho_m \frac{\Delta{(\frac{v_m^2}{2g_c}})}{\Delta h}[1]

where

 \bar \rho_m = \rho_L (1-H_g) + \rho_g H_g, slip mixture density
 \rho_m = \rho_L C_L + \rho_g (1-C_L) , no-slip mixture density

Colebrook–White [2] equation for the Darcy's friction factor:

 \frac{1}{\sqrt{f}}= -2 \log \left( \frac { \varepsilon'} {3.7 D} + \frac {2.51} {\mathrm{Re} \sqrt{f}} \right)[3]

Reynolds two phase number:

 Re = 2.2 \times 10^{-2} \frac {q_L M}{D \mu_L^{H_L} \mu_g^{(1-H_L)}}

Discussion

Workflow Hg

 N_V = 453.592\ \frac{{\rho_m}^2 {v_m}^4}{g_c \sigma_L (\rho_L - \rho_g)} [1]
 N_D = 453.592\ \frac{g_c (\rho_L - \rho_g) D^2}{\sigma_L }
 R = \frac{v_{SL}}{v_{SG}}
 B = 0.0814 \left ( 1 - 0.554\ \ln \left (1 + \frac{730 R}{R+1} \right )  \right )
 A = -2.2314 \left ( N_V \left (1 + \frac{205}{N_D} \right )  \right )^B
 H_g = \frac{1-e^A}{R+1}

Workflow ε'

Nomenclature

NV velocity number

References

  1. 1.0 1.1 1.2 Gray, H. E. (1974). "Vertical Flow Correlation in Gas Wells". User manual for API 14B, Subsurface controlled safety valve sizing computer program. API. 
  2. Colebrook, C. F. (1938–1939). "Turbulent Flow in Pipes, With Particular Reference to the Transition Region Between the Smooth and Rough Pipe Laws"Paid subscription required. Journal of the Institution of Civil Engineers. London, England. 11: 133–156. 
  3. Moody, L. F. (1944). "Friction factors for pipe flow"Paid subscription required. Transactions of the ASME. 66 (8): 671–684.