×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

POSTED ALSO IN SPREADSHEETS FORUM

POSTED ALSO IN SPREADSHEETS FORUM

POSTED ALSO IN SPREADSHEETS FORUM

(OP)
POSTED ALSO IN SPREADSHEETS FORUM
I've a spreadsheet for plotting pump curves on one chart but the problem is in adding the abscissa (x, flow) values for the same ordinate (y, head) values. The two curves are not input with common y-values.  The fastest way seems to be to plot out the two pump curves on one chart then create the combined curve manually by hand with a ruler. Presentation isn't the best. Pump supplier software is geared for their pumps alone and I want to be able to superimpose a couple different mfgr's pump curves on my system curves. Any ideas?

RE: POSTED ALSO IN SPREADSHEETS FORUM

drain:

Maybe I'm missing the problem, but do you have both the X (flow) and y (pressure) data for both pumps?  If so, just do an XY plot (if using Excel) with all X values in one column and the first pump's y data in column 2, the 2nd pump's y data in column 3.  The easy way to do this is to paste the X and Y data from the first pump in the 1st two columns.  Then do the same for pump 2, but aligning the X values under pump ones.  Then move the 2nd y values over to the 3rd column, sort by X and plot the two series.

To do it digitally, buy the real Adobe Acrobat program that allows you to print directly to a pdf file and do so for both pumps.  Then fire up Adobe Illustrator (if you have access toit) and you can scale the entities to match and even change colors!  

RE: POSTED ALSO IN SPREADSHEETS FORUM

(OP)
HomeMadeSin
I have two plots with different y values and common x values. But I need to add the x values together for common y-values. I don't have common y values for the two plots so I need to generate them, so I can add the corresponding x values together to get my ultimate plot. Basically, I need an algorithm to fit my existing curves so I can generate additional x and y values.

RE: POSTED ALSO IN SPREADSHEETS FORUM

drain:

It must be the fact that it is the end of the day.  I'm not following you.  I can't see the need to add x values (flow) together for common y values (head).  You are looking at Pump A and Pump B for a given system curve, yes?  So, you would have 3 curves on a single chart: system, pump a and pump b?

RE: POSTED ALSO IN SPREADSHEETS FORUM

(OP)
Here's the data, my friend. Common flow. Different heads. Plot them out. Then generate new heads so the curves can be added together for common head.


Q     H-1     H-2
0    274.3    286.5
25    271.3    283.5
50    268.3    277.4
75    262.7    270.6
100    253.6    263.0
125    241.4    254.5
150    226.5    247.5
175    207.3    238.6
200    180.7    229.2
225    147.2    218.8
250    109.7    210.3
275             201.2
300             190.5
325             179.8
350             166.7
375             153.9
400             135.9

RE: POSTED ALSO IN SPREADSHEETS FORUM

Unless you're trying to operate the two pumps either in series or in parallel,there is no need to add either ordinates or absicca. It looks like you can throw away all values of H-2 smaller than 210.3.  That will give you equal numbers of x-y coordinates and simplify your task.  Next you need to calculate the system head curve over the same range of flows.  Then you should be able to plot all three curves and find the points of intersection, i.e. the operating points for each pump.  

Do we understand your question correctly ? Are you trying to operate these two pumps in series ?

RE: POSTED ALSO IN SPREADSHEETS FORUM

Drain:

I thought you were confused until I started to make a sheet for you.  You are using flow as a constant number (i.e.: 25, 50, 75 etc.) and trying to vary the head.  Try using the pump head as your constant number and very the flow(s) to match the constant head.  I think that should work.

Let me know

Good Luck!

RE: POSTED ALSO IN SPREADSHEETS FORUM

(OP)
parallel pumping is precisely the reason i want to add them.

RE: POSTED ALSO IN SPREADSHEETS FORUM

I think D23 has got it.  Parallel pumping with two different pumps is what I missed.

RE: POSTED ALSO IN SPREADSHEETS FORUM

drain:

I don't think I explained very well.  I made a quick graph sheet that will show you what I mean and it actually worked .  If you would like it send me an email.

davidlsus@yahoo.com

Good Luck!
David

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

eBook - Integrating the Engineering Ecosystem
Aras Innovator provides multiple options for integrating data between systems, depending on the scenario. Utilizing the right approach to meet specific business requirements is vital. These needs range from authoring tools, federating data from various and dissimilar databases, and triggering processes and workflows. Download Now
Research Report - Simulation-Driven Design for SOLIDWORKS Users
In this engineering.com research report, we discuss the rising role of simulation and the paradigm shift commonly called the democratization of simulation. In particular, we focus on how SOLIDWORKS users can take advantage of simulation-driven design through two analysis tools: SOLIDWORKS Simulation and 3DEXPERIENCE WORKS. Download Now
White Paper - Industry 4.0 and the Future of Engineering Education
With industries becoming more automated, more tech-driven and more complex, engineers need to keep their skills and knowledge up to date in order to stay on top of this wave—and to be prepared for the Industry 4.0 future. The University of Cincinnati offers two online Master of Engineering degree programs designed specifically for practicing engineers. Download Now
eBook - The Design Gridlock Manifesto
In this eBook, you’ll learn 6 ways old CAD technology slows your company down and hear how design teams have put those problems to rest. “The Design Gridlock Manifesto” shares first-hand modern CAD experiences from 15 companies around the world. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close