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Piecewise Polynomial of Function

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Old   December 13, 2015, 07:09
Default Piecewise Polynomial of Function
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Onur
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Hi,

I was using serial value in piecewise polynomial in fluent.

But couldnt understand a photo shown below.

What does places where I have selected in photos stand for?

https://imageshack.com/i/hl1Xdkgbp

Range 1 and Ranges 2 defined in photos what exactly does it mean?

Kind Regards,
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Old   December 14, 2015, 01:03
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In the upper right: Ranges specifies the number of ranges (number of pieces of your piecewise polynomial)

On the left: Range # lets you specify the coefficients for a particular range, the range is specified via minimum and maxmimum value for the range.

Last edited by LuckyTran; December 15, 2015 at 00:58.
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Old   December 14, 2015, 03:41
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Quote:
Originally Posted by LuckyTran View Post
In the upper right: Ranges specifies the number of ranges (number of pieces of your piecewise polynomial)

On the left: Range # lets you specify the coefficients for a particular range, the range is specified via minnimum and maxmimum value for the range.
Hi LuckyTran,

In upper right ranges, if ranges is exceeded, the better result is,

But on the left range is still complicated because I couldnt understand exactly.I have given coefficients of what I should calculate,If the range is changed by up ( or exceeded),what does it happen or give an result?

Kind Regards,
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Old   December 15, 2015, 00:57
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Quote:
Originally Posted by Onurozcan View Post
Hi LuckyTran,

In upper right ranges, if ranges is exceeded, the better result is,

But on the left range is still complicated because I couldnt understand exactly.I have given coefficients of what I should calculate,If the range is changed by up ( or exceeded),what does it happen or give an result?

Kind Regards,
Sorry I can't understand what you're asking.

The upper right specifies the number of pieces (number of ranges) to the polynomial. In the picture, you have specified that there are two ranges (two different polynomials to your problem).

Now on the left, you are selecting a particular range and specifying the coefficients for that range. In the image, you have selected Range 1. You then specify the minimum (300), maximum (1000) for Range 1. You also specify the number of polynomial coefficients (5). Then you have to specify these five polynomial coefficients.

Now you need to also do the same procedure for Range 2 by clicking that up arrow next to Range 1.
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Old   December 15, 2015, 16:10
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Quote:
Originally Posted by LuckyTran View Post
Sorry I can't understand what you're asking.

The upper right specifies the number of pieces (number of ranges) to the polynomial. In the picture, you have specified that there are two ranges (two different polynomials to your problem).

Now on the left, you are selecting a particular range and specifying the coefficients for that range. In the image, you have selected Range 1. You then specify the minimum (300), maximum (1000) for Range 1. You also specify the number of polynomial coefficients (5). Then you have to specify these five polynomial coefficients.

Now you need to also do the same procedure for Range 2 by clicking that up arrow next to Range 1.

Hi LuckyTran,

Thank you for replying,

What I mean is shown below:

for ex.

Cp(T) 0<T<300 Cp= 1.52T+0.51
300<T<900 Cp = 0.88T2(square) - 1.6T +0.82

in upper right range is 2

in left right, range 1 and 2 will be separetly specified what coefficients are needed.

But I have just one equation for one range (278.15 K and 1093.15 K )

That's why I need to choose ''1'' in upper right field as well as left right when I put all coef.

Kind Regards,
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