Cv is the specific heat capacity at constant volume, and Cp is the specific heat capacity at constant pressure.
The calculation object of constant volume specific heat capacity is gas. Because under the condition of constant pressure, when the temperature of the gas rises, the gas must expand and do work to the outside. In addition to the heat required for temperature rise, a part of the heat is also needed to compensate for the work done by the gas. Therefore, the constant pressure of the gas The specific heat capacity is larger than the specific heat capacity at constant volume. Extended information
The definitions of specific heat capacity at constant pressure and specific heat capacity at constant volume are applicable to all working fluids.
Since the gas expands when heated under constant pressure, the heat absorbed not only increases the thermodynamic energy, but also overcomes external forces to perform work. Therefore, the specific heat capacity at constant pressure is greater than the specific heat capacity at constant volume. The difference is 1 Kg gas is sprayed to the outside during the process of heating up under constant pressure.
The specific heat capacity of a gas at constant pressure is larger than the specific heat capacity at constant volume. Since solids and liquids do not change their physical state, the heat supplied from the outside is used to change the temperature, and the volume itself does not change much, so the difference between the constant pressure specific heat capacity and the constant volume specific heat capacity of solids and liquids is not too big. Therefore no distinction is needed.
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