Use of Steam Tables

JaredJames

hi, i am a first year aerospace engineering student and have just completed the Thermodynamics section of my course.
My problem is, that i understand all topics except steam tables.

I have absolutely no idea how to use them, and no idea what the calculations associated with them are. (e.g. quality, enthalpy, volume occupied by vapour release).

I would really appreciate somehelp on this as my exam is in two days.

Many Thanks
Jared James

Q_Goest

Steam tables are nothing more than a list of various properties of water at any given pressure and temperature. Since water changes phase, it's useful sometimes to have the properties over the entire range of liquid to vapor. Enthalpy, internal energy, entropy, etc... are all just properties of the fluid. They also make it much easier to apply first law calculations such as dU = Hin - Hout +Qin etc... since you can apply the first law directly if you have the value for the properties of internal energy, enthalpy ...

stewartcs

For most substances, the relationships among thermodynamic properties are too complex to be expressed by simple equations. Therefore, properties are frequently presented in the forms of tables. Some thermodynamic properties can be measured easily, but others cannot and are calculated by using the relations between them and measurable properties. The results of these measurement and calculations are presented in tables (steam in your case).

By knowing two independent intensive properties of a substance, you can describe the state of the substance.

Using the tables depends on the problem you are trying to solve. If you have a specific problem, then describe it and we'll be able to walk you through it so you can see how the tables are used.

Hope that helps.

CS