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Old   July 5, 2004, 00:39
Default Energy balance
  #1
Julie Polyakh
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Hello,

Does somebody know how to calculate energy balance at two cross sections (not inlets or outlets)?

Best Regards,

Julie
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Old   July 5, 2004, 03:22
Default Re: Energy balance
  #2
Richard
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In v3.20 there's a new thing called internal boundaries which can do this.
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Old   July 5, 2004, 03:40
Default Re: Energy balance
  #3
Julie Polyakh
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And what about v3.150A?..
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Old   July 5, 2004, 06:15
Default Re: Energy balance
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Thomas
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what about calculating the enthalpy difference (cp *dT) between these two cross sections?

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Old   July 5, 2004, 08:23
Default Re: Energy balance
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Julie Polyakh
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Nice, but in my simulation Cp=Cp(T). Which Cp value should I take in such a case?
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Old   July 5, 2004, 13:50
Default Re: Energy balance
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Panos
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You can use the formula Cp=a+bT+cT^2+dt^3 where the constants can be found in any book of physics and chemistry or thermodynamics. hope it is helpful
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Old   July 5, 2004, 13:52
Default Re: Energy balance
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4xF
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You could try to write a macro for integrating between two surfaces mdot*Cp*T = H, where H is the enthalpy, T is the temperature, Cp is your local Cp(T) and m is the mass flux (mdot= rho*S*V, S is the surface, V is the velocity). Ask also your local support office, they MUST have a macro ready for that.
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Old   July 6, 2004, 03:19
Default Re: Energy balance
  #8
Thomas
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yes ans you can also use the operate command for this. you have 6 post registers to do this operation, thast should be enough!

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Old   July 7, 2004, 03:58
Default Re: Energy balance
  #9
Julie Polyakh
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Yes, Panos, I know. But there is also the chemical energy of unburned fuel that I have to take into account.

Regards,

Julie
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Old   July 7, 2004, 04:00
Default OK. Thanks
  #10
Julie Polyakh
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