以流体力学三大守恒方程为基础，建立了等温和非等温条件下的燃气管网稳态和动态仿真理论模型。

The theoretical dynamic simulation models for stationary flow and transient flow under the isothermal and non-isothermal condition are set up based on the three conservation equations.

youdao

动量守恒原理则不管内力的性质如何（保守的或非保守的）都能适用。

The principle of conservation of momentum holds whatever the nature of the internal forces, conservative or not.

youdao

必须记住，动量守恒甚至对于非弹性碰撞也是成立的，尽管这时动能已不守恒。

It is important to realize that momentum conservation applies even to inelastic collisions, in which the kinetic energy is not conserved.

youdao