等温条件下可压缩理想气体的伯努利方程

THE BERNOULLI'S EQUATION OF COMPRESSIBLE IDEAL GAS UNDER THE ISOTHERMAL CONDITION

不可压缩流体的伯努利方程在解释飞机机翼升力时出现了矛盾.从这个矛盾出发,本文建立理想气体的等温过程模型,运用能量守恒推导出了等温条件下可压缩理想气体的伯努利方程.通过比较分析可知:不可压缩理想气体的伯努利方程在等温条件下形式上可变成等温可压缩理想气体的伯努利方程,但本质上是有区别的;与等熵条件下的伯努利方程比较,两者成立条件不同,方程的形式也不一样;等温条件与等焓条件在本质上是一致的,伯努利方程形式和本质都不变.

Bernoulli＇s equation of incompressible fluid appeared to be a contradiction when explaining the lift force on wing of airplane.From this point of contradiction,the model of isothermal process of ideal gas was established in this paper,and the Bernoulli＇s equation of compressible ideal gas under the isothermal condition was derived by using the law of conservation of energy.Through comparison and analysis,we knew that the Bernoulli＇s equation of incompressible ideal gas had the same form as the Bernoulli＇s equation of compressible ideal gas under the isothermal condition,but they were different in substance.Compared with Bernoulli＇s equation under the isentropic condition,the two had different forms and were suitable for different situations.The isothermal condition was the same as the isenthalpic condition,so the form and substance of the Bernoulli＇s equation were same in two conditions.