相似条件（conditions of similarity）指的是在模型实验中，模型与实物间必须保持某种关系，即需要满足若干基本条件，才能保证模型与实物的相似，这些基本条件或相互关系称为“相似条件”。
指出了质量分布的差别引起相似条件的变化。
The paper also points out that the difference of quality distribution causes changes of similar conditions.
对于理想弹性体来说，时间相似条件早已明确。
For an idealized elastic mass, similarity conditions for time has been established for a long time.
假设温度减推力起飞的风扇转速由发动机相似条件计算。
The rotation speed of the fan under assumed temperature reduced thrust takeoff is calculated based on the analogical condition of engine.
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