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1-Visitor
July 9, 2021
Solved

2 equations 2 unknowns... Know this has been done to death but could really use help.

  • July 9, 2021
  • 2 replies
  • 1506 views

Hello,

 

Mathcad Prime 7 n00b user here. I am trying to solve these two equations (pictured) by iteration without a previous value defined for Q but it is really stumping me. Currently I have Q defined but when it is undefined it really throws everything off and I am stuck. I will attach pictures and a file, feel free to edit as needed.

Capture.PNG

Capture1.PNG

Thanks!

 

 

Best answer by Fred_Kohlhepp

First of all--Mathcad understands units, USE THEM!

 

Second, did you really mean million cubic feet per hour?

Fred_Kohlhepp_0-1625860808031.png

Because if I put that thru a six inch pipe, it's going really fast:

Fred_Kohlhepp_1-1625860915677.png

Third, your equation for Reynold's Number doesn't balance:

Fred_Kohlhepp_2-1625861039585.png

File attached.

2 replies

1-Visitor
July 9, 2021

I tired using a for loop but I cannot seem to get it to work.

23-Emerald I
July 9, 2021

First of all--Mathcad understands units, USE THEM!

 

Second, did you really mean million cubic feet per hour?

Fred_Kohlhepp_0-1625860808031.png

Because if I put that thru a six inch pipe, it's going really fast:

Fred_Kohlhepp_1-1625860915677.png

Third, your equation for Reynold's Number doesn't balance:

Fred_Kohlhepp_2-1625861039585.png

File attached.