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Homework Help: Gas turbine brayton cycle thermodynamic mass flow rate of air

  1. Apr 28, 2012 #1
    1. The problem statement, all variables and given/known data

    a gas turbine is designed to produce 3000hp when using air at a maximum inlet temperature of 650k and assuming a heat loss of 70 kj/s. if the exhaust temperature is desired to be no greater than 200 degrees celsius, determine the mass flow rate of air required.

    2. Relevant equations
    in the textbook the only things i can find are this formula
    Qadd = mcp(t3-t2)
    or Qrej = mcp (t1-t4)

    but the problem is that solving with these with Qadd/cp(t3-t2) im not sure if that would be correct using the figures given in this problem because it gives you an exhaust temperature and a max inlet temp.

    3. The attempt at a solution

    im having trouble coming up with the needed equation to determine the mass flow rate. any infromation would be highly appreciated as to the formula needed to find the mass flow rate.
  2. jcsd
  3. Apr 28, 2012 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Welcome to PF! Say, it's rather weird that they threw in HP along with all the metric units -- plus they used both K and °C -- but so be it.

    It would seem that the 1st Law, ΔU=Q-W, should work here. You know what Q and W are for, say, a 1 second time duration.
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