Nov 9, 2006 #1 kunletee Mechanical Joined Nov 9, 2006 Messages 10 Location CA Dear all, I am having difficulty in solving this problem in c++. 1/sqrt(f)=2*log10(Re*sqrt(f))/2.51 It is required to calculate f. Re is given as 128592.72. Thanks. Kunletee
Dear all, I am having difficulty in solving this problem in c++. 1/sqrt(f)=2*log10(Re*sqrt(f))/2.51 It is required to calculate f. Re is given as 128592.72. Thanks. Kunletee
Nov 9, 2006 #2 nbucska Electrical Joined Jun 1, 2000 Messages 2,191 Location US Both sides are monotonous functions of F. Rearrange it: 0= 2*log10(Re*sqr(F))-2.51/sqr(F) ; Replace 0 with Y. Select an arbitrary value for F and calculate Y Change it with dF and recalculate. Put a straight line across these two points - solve its zero xing. Replace this into F and repeat until Y=0 Plesae read FAQ240-1032 My WEB: <http://geocities.com/nbucska/> Upvote 0 Downvote
Both sides are monotonous functions of F. Rearrange it: 0= 2*log10(Re*sqr(F))-2.51/sqr(F) ; Replace 0 with Y. Select an arbitrary value for F and calculate Y Change it with dF and recalculate. Put a straight line across these two points - solve its zero xing. Replace this into F and repeat until Y=0 Plesae read FAQ240-1032 My WEB: <http://geocities.com/nbucska/>