# Ratio of specific heats

(Difference between revisions)
 Revision as of 10:11, 12 September 2005 (view source)Praveen (Talk | contribs)← Older edit Revision as of 10:52, 12 September 2005 (view source)Jola (Talk | contribs) mNewer edit → Line 1: Line 1: - The ratio of specific heats (also known as ''adiabatic index''), usually denoted by $\gamma$ is the ratio of specific heat at constant pressure to the specific heat at constant volume + The ratio of specific heats (also known as ''adiabatic index''), usually denoted by $\gamma$, is the ratio of specific heat at constant pressure to the specific heat at constant volume. - $+ :[itex] - \gamma = \frac{C_p}{C_v} + \gamma \equiv \frac{C_p}{C_v}$ [/itex] - The adiabatic index always exceeds unity; for a polytropic gas it is constant. For monatomic gas $\gamma=5/3$, and for diatomic gases $\gamma=7/5$, at ordinary temperatures. For air its value is close to that of a diatomic gas, 7/5. + The adiabatic index always exceeds unity; for a polytropic gas it is constant. For monatomic gas $\gamma=5/3$, and for diatomic gases $\gamma=7/5$, at ordinary temperatures. For air its value is close to that of a diatomic gas, 7/5 = 1.4. + + Sometimes $\kappa$ is used instead of $\gamma$ to denote the specific heat ratio.

## Revision as of 10:52, 12 September 2005

The ratio of specific heats (also known as adiabatic index), usually denoted by $\gamma$, is the ratio of specific heat at constant pressure to the specific heat at constant volume.

$\gamma \equiv \frac{C_p}{C_v}$

The adiabatic index always exceeds unity; for a polytropic gas it is constant. For monatomic gas $\gamma=5/3$, and for diatomic gases $\gamma=7/5$, at ordinary temperatures. For air its value is close to that of a diatomic gas, 7/5 = 1.4.

Sometimes $\kappa$ is used instead of $\gamma$ to denote the specific heat ratio.