- #1
uby
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Pressure and velocity changes with temperature in open flow tube
Hello everyone,
I have a process in which a gas goes through a heater. I want to calculate the physical properties of the stream coming out of the heater. Here is a description of the streams:
Input to the heater:
molar flow rate is 1 mole per minute
pressure(P) is 2 atm
temperature(T) is 298K
gas velocity(u) is 1 cm per second
Output from the heater:
molar flow rate is 1 mole per minute
pressure is unknown
temperature is 1073K
gas velocity is unknown
How do I go about solving for the pressure and velocity of the output, assuming that the gas is compressible (i.e. - the density is free to change)?
Assuming an ideal gas equation of state: P = rho*R*T/M where rho = density, R = gas constant, and M = molar mass of the gas species.
Continuity (molar flux in equals molar flux out) requires that the molar flow rates be equal, but not necessarily the volumetric flow rates since density is free to change.
I end up getting stuck at the equation when combining ideal gas and continuity expressions:
P1*u1*T2/T1 = P2*u2
I cannot figure out how P2 and u2 individually change.
Help?
Thanks!
Hello everyone,
I have a process in which a gas goes through a heater. I want to calculate the physical properties of the stream coming out of the heater. Here is a description of the streams:
Input to the heater:
molar flow rate is 1 mole per minute
pressure(P) is 2 atm
temperature(T) is 298K
gas velocity(u) is 1 cm per second
Output from the heater:
molar flow rate is 1 mole per minute
pressure is unknown
temperature is 1073K
gas velocity is unknown
How do I go about solving for the pressure and velocity of the output, assuming that the gas is compressible (i.e. - the density is free to change)?
Assuming an ideal gas equation of state: P = rho*R*T/M where rho = density, R = gas constant, and M = molar mass of the gas species.
Continuity (molar flux in equals molar flux out) requires that the molar flow rates be equal, but not necessarily the volumetric flow rates since density is free to change.
I end up getting stuck at the equation when combining ideal gas and continuity expressions:
P1*u1*T2/T1 = P2*u2
I cannot figure out how P2 and u2 individually change.
Help?
Thanks!
Last edited: