# AahhhGG! Another Thermodyanmics Problem

1. Apr 19, 2005

### Naeem

Q. Steam is leaving a pressure cooker whose operating pressure is 30 psia. It is observed that the amount of liquid in the cooker ahs decreased by 0.4 gal in 45 minutes after the steady operating conditions are established, and the cross sectional area of the exit opening is 0.5 in^2. Determine

a) the mass flow rate of the steam and the exit velocity.

b) the total and flow energies of the steam per unit mass, and

c) the rate at which energy is leaving the cooker by steam.

a) Mass flow rate : density * Area of cross section * velocity

We know the area of cross section. How to figure out density and velocity

well,, 0.4 gallons in 45 minutes. [ Can we use this info, to find out the velocity ]

I also know Emass = mh

Ein = mass * h1 ( h1 - enthalpy / per unit mass ) can we find hg from tables, if so at what temp, we need to find., well pressure is given to be 30 psia.

Eout = mass * h2 ( h2-enthalpy / per unit mass ) phase 2 can we find hg for this phase 2,......

Any ideas/Help, appreciated

Thanks