e-NTU generic table dimensions discrepancy

Why by default in the e-NTU heat transfer block both NTU and Cr vectors are 5 dimensional but resulting effectiveness table is 5x6? Where is the last dimension coming from?

[Yifeng Tang]

The default vector of NTU, on my end, is [.5, 1, 2, 3, 4, 5], a 1x6 vector. The default of CR is [0, .25, .5, .75, 1], 1x5 vector. The effectiveness table is 6x5.

Is that not what you have as default?

Answer 1

[Muskan]

Hi Georgiy,

As per my understanding, the additional dimension in the effectiveness table comes from the inclusion of a "0" value in the Cr vector. The Cr vector represents the capacity ratio, which is the ratio of heat capacities between the hot and cold fluid streams. The "0" value in the Cr vector corresponds to the case when the heat capacity of the hot fluid stream is negligible compared to the cold fluid stream.

You can refer to the following documentation for a better understanding of the question:

https://in.mathworks.com/help/hydro/ref/entuheattransfer.html

I hope the above information helps resolve your query.

Thanks