THE SPECIFIC HEAT AND BASIC CHARACTERISTIC OF THE POLYTROPIC PROCESS OF IDEAL GASES

According to the characteristic that the polytropic exponent in the equation of the polytropic process of ideal gases remains the same, it is expounded that the specific heat of the polytropic process is closely related to the specific heat at constant volume of ideal gases. When the specific heat at constant volume of ideal gases is constant, all the thermodynamic processes with constant specific heat are classified as the polytropic processes of ideal gases, and there is no forbidden area for the value of the polytropic exponent. However, when the specific heat at constant volume of ideal gases varies with temperature, the thermodynamic processes with constant specific heat do not belong to polytropic processes, such as the adiabatic process with the zero specific being not a polytropic process, and there is a forbidden area for the value of the polytropic exponent. Only when the specific heat of a thermodynamic process resembles the specific heat at constant volume of ideal gases and has the same temperature dependency, can the thermodynamic process be a polytropic process of ideal gases. The basic characteristic of the polytropic process of ideal gases is that the difference between the specific heat of the process and the specific heat at constant volume is constant.