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(Bug?) HP48 Equation Library
02-13-2017, 02:50 AM (This post was last modified: 02-13-2017 02:54 AM by Mark Hardman.)
Post: #7
RE: (Bug?) HP48 Equation Library
(02-13-2017 01:39 AM)Han Wrote:  The "system" in the equation library is literally that one formula. So all on its own, the \( c \) seems extraneous to me.

It would look like the inclusion of c in certain beam equations is superfluous--only being used in Simple Deflection and Simple Slope.

(02-13-2017 01:39 AM)Han Wrote:  EDIT2: Ok, so it looks like the \( f \) in the first formula is FANNING(\(\epsilon / D, Re\) ) where the Reynolds constant is calculated as \( Re = D\cdot v_\text{avg} \cdot \rho / \mu \). The manual says that the Fanning function essentially uses two formulas depending on the whether Re is larger or smaller than 2100. So what are these two formulas?

For non-turbulent flow (Re<=2100), the function returns \(16/Re\). \(\epsilon / D\) is not even considered.

For turbulent flow (Re>2100), it looks like the function is using the equation (implicit in \(f\)) defined in this Wikipedia article: Fanning friction factor.

I lack your obvious skill with Latex, otherwise I would reproduce the formula here. I only tested a few data points (4) but all agreed with the Wikipedia article.

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Messages In This Thread
(Bug?) HP48 Equation Library - Han - 02-12-2017, 03:36 PM
RE: (Bug?) HP48 Equation Library - Han - 02-13-2017, 12:25 AM
RE: (Bug?) HP48 Equation Library - Han - 02-13-2017, 01:39 AM
RE: (Bug?) HP48 Equation Library - Mark Hardman - 02-13-2017 02:50 AM
RE: (Bug?) HP48 Equation Library - Han - 02-13-2017, 05:11 AM
RE: (Bug?) HP48 Equation Library - Vtile - 02-13-2017, 04:03 PM
RE: (Bug?) HP48 Equation Library - Han - 02-13-2017, 02:59 AM
RE: (Bug?) HP48 Equation Library - Han - 02-13-2017, 06:08 PM
RE: (Bug?) HP48 Equation Library - Han - 02-14-2017, 03:57 AM
RE: (Bug?) HP48 Equation Library - Han - 02-14-2017, 07:08 PM
RE: (Bug?) HP48 Equation Library - Han - 02-14-2017, 03:36 AM
RE: (Bug?) HP48 Equation Library - Han - 02-14-2017, 04:16 AM
RE: (Bug?) HP48 Equation Library - Han - 02-19-2017, 10:53 PM
RE: (Bug?) HP48 Equation Library - Han - 03-06-2017, 07:51 PM
RE: (Bug?) HP48 Equation Library - Han - 03-06-2017, 05:31 PM



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