流动的气体所具有的焓与动能之和，表示其总能量，就是说,气体的总能量取决于气体的状态参数温度T与速度c。当气流与外界没有能量交换,按照定嫡过程将气体速度完全滞止到零时所对应的温度称为滞止温度(又称总温,以T.表示。它也是气体的一个状态参数。如果流动的气体与速度被滞止到零的气流具有相同的总能量，则可用气体状态参数工。来表示其总能量,即:
    相应于滞止温度的焓称为滞止馆(或总焓)，以h.表示:
[例3- 1]试确定某油田气在压力为30X10Pa和温度为90C时的比热容比、温度绝热指数kt及容积绝热指数Kv。  已知油田气组分为:
(1)查各组分气体的参数:
(2)求混合器的摩尔质量M及各组分质量分数gi：

(3)求油田气当量临界参数与对比参数：

油田气当量临界温度：

油田气当量临界压力

对比压力

对比温度

(4)求比热容比：

混合气的比定压热容为、；

查图3-6(a)得：

查图3-6(b)得：

比热容比：

(5)求kt及kv：

由图3-7和图3-8查得：X=0.2，Y=1.02。

混合气气体常数：

查得3-5得压缩因子：Z=0.97。

可见

The sum of enthalpy and kinetic energy of a flowing gas represents its total energy, which means that the total energy of a gas depends on its state parameters, temperature T and velocity c. When there is no energy exchange between the airflow and the outside world, the temperature corresponding to the complete stagnation of the gas velocity to zero according to the stagnation process is called the stagnation temperature (also known as the total temperature, represented by T.). It is also a state parameter of the gas. If the flowing gas has the same total energy as the airflow whose velocity is stagnated to zero, the gas state parameter can be used to represent its total energy, that is:

The enthalpy corresponding to the stagnation temperature is called the stagnation enthalpy (or total enthalpy), denoted by h express:

[Example 3-1] Determine the specific heat capacity ratio, temperature adiabatic index kt, and volume adiabatic index Kv of a certain oilfield gas at a pressure of 30X10Pa and a temperature of 90C. The known composition of oilfield gas is:

(1) Check the parameters of each component gas:

(2) Calculate the molar mass M of the mixer and the mass fraction gi of each component:

(3) Calculate the critical and comparative parameters of oil field gas equivalence:

Oil field gas equivalent critical temperature:

Oilfield gas equivalent critical pressure

reduced pressure

reduced temperature

(4) Calculate the specific heat ratio:

The specific heat capacity at constant pressure of the mixture is;

According to Figure 3-6 (a):

According to Figure 3-6 (b):

Specific heat ratio:

(5) Request kt and kv:

According to Figures 3-7 and 3-8: X=0.2，Y=1.02。

Gas constant of mixed gas:

Calculate the compression factor of 3-5: Z=0.97。

it is thus clear  that