Spreadsheet for Friction Factors

Engineering Software general discussion Spreadsheets
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#1

By quark:

I prepared an excel spreadsheet to calculate various friction factor expressions (both implicit and explicit), and thought to share not because it is too difficult to do, but to avoid the waste of our cumulative time writing lengthy expressions:

PROCEDURE

  • Enter values of Reynolds Number in [C4] and e/D in [F4]

For Churchill Equation

  • enter the code of A =POWER(-2.457LN((POWER((7/C4),0.9)+(0.27F4))),16) in [C16] and of B =POWER((37530/C4),16) in [C17]
    Enter the code of f =8*POWER(((POWER((8/C4),12))+(1/(POWER((C16+C17),1.5)))),(1/12)) in [C18]

For Sherghides equation

  • A =-2*(LOG((F4/3.7)+(12/C4))) in [C30]
  • B =-2*(LOG((F4/3.7)+(2.51*C30/C4))) in [C31]
  • C =-2*(LOG((F4/3.7)+(2.51*C31/C4))) in [C32]
  • f =POWER((C30-((POWER((C31-C30),2))/(C32-(2*C31)+C30))),-2) in [C33]

For Moody Equation

  • F =(5.5/1000)(1+(POWER(((210000*F4)+(1000000/C4)),1/3))) in [C39]

For Wood Equation

  • a =-1.62*(POWER(F4,0.134)) in [C46]
  • f =((0.094*(POWER(F4,0.225)))+(0.53F4)+(88(POWER(F4,0.44))*(POWER(C4,C46)))) in [C47]

For Jain Equation

  • f =1/(POWER((1.14-(2*LOG(F4+(21.25/(POWER(C4,0.9)))))),2)) in [C54]

For Chen Equation

  • A =LOG(((POWER(F4,1.1098))/2.8257)+(5.8506/(POWER(C4,0.8981)))) in [C62]
  • f =1/(POWER((-2LOG((F4/3.7065)-(5.0452C62/C4))),2)) in [C63]

For Zigrang and Sylvester Equation

  • A =LOG((F4/3.7)-((5.02/C4)*(LOG((F4/3.7)+(13/C4))))) in [C71]
  • f =1/(POWER((-2LOG((F4/3.7)-(5.02C71/C4))),2)) in [C79]

For Colebrook Equation

  • Enter initial f value as 0.02 in [C85]
    And copy the following formul[
    =1/(POWER((-2LOG((F4/3.7)+(2.51/(C4(POWER(C85,0.5)))))),2)) in [D87]
    =1/(POWER((-2LOG((F4/3.7)+(2.51/(C4(POWER(D87,0.5)))))),2)) in [E87]
    =1/(POWER((-2LOG((F4/3.7)+(2.51/(C4(POWER(E87,0.5)))))),2)) in [F87]
    =1/(POWER((-2LOG((F4/3.7)+(2.51/(C4(POWER(F87,0.5)))))),2)) in [G87]
    =1/(POWER((-2LOG((F4/3.7)+(2.51/(C4(POWER(G87,0.5)))))),2)) in [H87]

[Generally G87 and H87 will have equal values(i.e Colebrook’s equation generally converges after 4th step of iteration) and this is your friction factor for the given Re and e/D]

Once you are done with making the spreadsheet, you can safely delete all those redundant rows from the spreadsheet.