Info

The specific heat at constant pressure (cP) or constant volume (cV) is the heat capacity per unit mass (m):

The difference of the thermal heat capacities (or specific heats) in an ideal gas is the gas constant (Rgas = 8.31 J Mole-1 K-1):

where NA is Avogadro's number, the number of particles in one mole (= 6.022 X1023 particles), and k is Boltzmann's constant.

Assume we have an atmosphere composed of an ideal gas which is convecting. A parcel of this air moves adiabatically (dQ = 0). Equation (6.10) then becomes dU = — PdV. (6.16)

Using the relationships in Eqs. (6.11) and (6.14), we find that cy dT = —PdV

The ratio of the specific heats, or thermal heat capacities, occurs often in thermo-dynamic applications and is indicated by the parameter y:

cv Cv

The adiabatic lapse rate of a dry atmosphere is obtained by combining the thermodynamic equation, equation of hydrostatic equilibrium, and ratio of the specific heats:

This is often rewritten as

Was this article helpful?

0 0
Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

Get My Free Ebook


Post a comment