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March 1, 2019, 02:26 |
Creation of New Nasa 7 Polynomial
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#1 |
New Member
Arun
Join Date: Mar 2019
Posts: 3
Rep Power: 7 |
can we create nasa polynomial for new species .I am going to create a new vegetable oil for blending with the diesel but in order to add the new species i don't know how to add if there is any method.
I am having the data for specific heat , enthalpy and entropy with respect to temperature but i donot know how to create the 7 coefficient polynomial |
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March 1, 2019, 14:51 |
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#2 |
Senior Member
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,676
Rep Power: 66 |
It's nothing special. You just curve fit the properties to a fourth order polynomial in Temperature. There are 7 coefficients, but 1 is for the reference enthalpy and 1 is for the reference entropy. See Nasa Polynomials.
Note that NASA thermodynamic files (or chemkin thermo files) contain two sets of coefficients (more than 7 coefficients total), one set is for the low temperature range and one for the high temperature range. |
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March 5, 2019, 02:53 |
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#3 |
New Member
Arun
Join Date: Mar 2019
Posts: 3
Rep Power: 7 |
TEMP ENTHALPY SPECIFIC HEAT ENTROPY
500 -105 30 60 750 -55 35 72 1000 -30 39 85 1250 -14 45 90 1500 -7 48 102 1750 1 50 112 2000 8 52 122 2250 15 55 125 2500 20 57 130 2750 24 59 135 the above table is our fuel property, does we need to solve the three property equation simultaneously. i donot know which software to use. could you please show us the right way? Thanks in advance |
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March 5, 2019, 08:45 |
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#4 |
Senior Member
Lucky
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 5,676
Rep Power: 66 |
What software do you have? Excel? Matlab? Other?
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March 5, 2019, 11:49 |
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#5 |
New Member
batman
Join Date: Nov 2017
Posts: 1
Rep Power: 0 |
I am having Excel.
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March 6, 2019, 02:35 |
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#6 |
New Member
Arun
Join Date: Mar 2019
Posts: 3
Rep Power: 7 |
Sir i used python to solve each equation individually and i get 5+6+7 coefficient.
5 coefficient for specific heat and 6 coefficient for enthalpy and 7 coefficient for entropy but i don't know how to obtain overall 7 coefficient for low range and high range temperature. |
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