(33E) Stream Flow Estimate in Culverts

[Dieter]

(03-09-2019 09:04 PM)Thomas Klemm Wrote:  

Quote:BTW the conversion constant actually is 0,3048^–1/3 = 1,4859...
If you manage to squeeze out one more step (which is possible) you can replace that 1,49 with the more exact value 1,486. ;-)

We can even use 1.4859 with the HP-25:

We can even use the exact value. ;-)

Sometimes you overlook the obvious: since the exact value is a cube root it can be factored into the one that is already calculated.

Code:

01 RAD
02 STO 0
03 RCL 1
04 X<>Y
05 -
06 RCL 1
07 /
08 COS-1
09 STO 4
10 RCL 1
11 *
12 RCL 1
13 RCL 0
14 -
15 RCL 4
16 SIN
17 *
18 -
19 RCL 1
20 *
21 PAUSE
22 RCL 4
23 RCL 1
24 2
25 *
26 *
27 /
28 x^2
29 .
30 3
31 0
32 4
33 8
34 /
35 3
36 1/x
37 Y^X
38 RCL 3
39 /
40 RCL 2
41 SQRT
42 *
43 PAUSE
44 *
45 LastX
46 X<>Y
47 DEG
48 GTO 00

For d=3,5 this yields a flow rate of 208,66 ft³/s.

And finally there is even one unused step left. Add your preferred display format if you like.

For metric units (input in m, output in m², m/s and m³/s) simply remove line 29...34.

Dieter