Excell formual for Torispherical Head Volume 1

[MIkkelPoulsen]

Hi

I'm trying to setup a excell sheet for scale solution for a water tank setup i'm doing.
For this i need to calculate the volume for a Torispherical Head - but I can not get the formula to work in Excell like I want it to, it does not give the correct volume.

Can somebody see what I have done wrong in my formula?

On the online calculator it gives: V=0,3017m3
online calculator:

https://www.vcalc.com/wiki/torispherical-head-volume-and-height

In my excell formula it give me: 0,3099m3
The size are:
R/D=1450mm
h=281,3mm
a=145mm
c=580 (calculated: c = D/2 - a)

My formula looks like this:
=(PI()/3)*((2*281,3*(1450^2))-((2*(145^2))+(580^2)+(2*145*1450))*(1450-281,3)+(3*(145^2)*580*(SIN((1450-281,3)/(1450-145))^-1)))

What i'm i doing wrong?

Thanks in advance.
Br
mikkel

 

[robyengIT]

what about of sin in radians ?

 

[HTURKAK]

Your expression will calculate the SIN of reciprocal (e.g. 1/X) of ((1450-281,3)/(1450-145))..

YOU SHALL USE ARCSIN ... ( SIN ^-1) is , ARCSIN..









Not to know is bad;
not to wish to know is worse.

NIGERIAN PROVERB

 

[MIkkelPoulsen]

Then the formula looks like this you mean
=(PI()/3)*((2*281,3*(1450^2))-((2*(145^2))+(580^2)+(2*145*1450))*(1450-281,3)+(3*(145^2)*580*(ASIN((1450-281,3)/(1450-145)))))

It gives me:
0,3034m3

Closer, but still a little off

 

[HTURKAK]

Probably round -off error.. You may post the detail of the Torispherical Head mit dimensions if you want a better respond







Not to know is bad;
not to wish to know is worse.

NIGERIAN PROVERB

 

[MIkkelPoulsen]

I have all the dimension here that i use in the formula:
The size are:
R/D=1450mm
h=281,3mm
a=145mm
c=580 (calculated: c = D/2 - a)

And here is the online calculation

 

[IFRs]

For clarity, I would use variables in your formula (named ranges). "Radius", "Height", "R-DRatio" etc.

The online calculator has a different "h" - can you track that down?

I would use ALt-Enter in the formula bar to put each parenhesis on a differet line.

Do a hand calc to make sure the intermediate results are correct.
I don't think round off would be a factor.
Excel should default to radians but you can check it out ie SIN(PI()/4) should be 0.707107

If you use Excel a lot, check out one of the AI-aided Formula Editors
one can be found at

https://www.10studio.tech/docs/introduction/

among other things they show you your fomula formatted in a way that may be easier to track down issuse.

 

[Geoff13]

I did this in Excel and agree with the screenshot of the online calc (h=280.97 mm and V = 0.3017 m³). I always use cell names (like IFRs suggested) to make formula debugging easier.

In your initial post you said h = 281.3 mm. When I use this value for h I get your volume (0.3034 m³), so it looks like your long Excel formula is OK, but your h calc is off a little.

 

[georgeverghese]

Using the much simplified expression for this in Perry for torispherical head where knuckle radius = 3 x dished head thickness, I get V = 0.303m3 for h=0.281m. This simpler expression is on page 10-140 in the 7th edn of Perry if you're interested.

 

[r6155]

For Decimal Ends R=D and r=0,1 D
V= 0,1 D*3 then 0,304 m3

Regards