how to understand and combine simscape pump performance curves

Hello

I'm working with pump performance data generated from Simscape in MATLAB, which includes curves for head, efficiency, brake power, and shaft torque, all plotted against capacity (flow rate). Currently these are individual graphs but I want to combine them into one graph.

My goal is to visualize how efficiency, brake power, and head correlate with each other over the range of capacities. Since these parameters have different units and scales, I need guidance on how to:

1. Normalize or Scale Data: What's the best approach to scale or normalize these different metrics so they can be plotted together in a meaningful way?
2. Plotting on the Same Graph: Could you provide advice or an example on how to plot these scaled or normalized curves on a single graph in MATLAB, ensuring that the relationship between them is clear?
3. Interpreting the Combined Graph: Once plotted, how would I interpret which region of the curve corresponds to high efficiency, optimal power usage, or maximum head? For example, how can I determine the capacity range where efficiency is at its peak while considering the head and brake power?

Any insights or examples on how to approach this would be greatly appreciated.

Answer 1

[Yifeng Tang]

I can try to help on the "Plotting on the Same Graph" part.

Once you generate this figure from the pump block, you can use the gcf command to get its handle and extract all the data from that. For example, you can get the data from the bottom right subplot using:

myFig = gcf;
Capacity = myFig.Children(2).Children(2).Children.XData;
Torque   = myFig.Children(2).Children(2).Children.YData;

Once you have the data arrays, you can do whatever you want with them, including plotting on the same graph.

Answer 2

[Kothuri]

Hi Muhammad Ali,

To combine the pump performance curves into one graph and interprete the relationships between head, efficiency, brake power, and shaft torque, you can follow the below steps:

• To compare parameters with different units, normalization or scaling is essential. You can use the "normalize" function for this purpose.
• Once the normalized data is obtained, you can plot all the curves on the same plot using "hold" function.
• After obtaining the combined graph, you can interprete from the graph the capacity range where the efficiency curve reaches its maximum which is the optimal operating range for energy use.
• Compare the head curve to the efficiency peak. This shows if the pump maintains high head while operating efficiently.
• High efficiency often corresponds to moderate brake power values, indicating energy-efficient operation.

You can refer the below documentation links for more info on:

• Normalization - https://www.mathworks.com/help/matlab/ref/double.normalize.html https://www.mathworks.com/help/matlab/math/normalize-data-with-differing-magnitudes.html
• "hold" function - https://www.mathworks.com/help/matlab/ref/hold.html