constant area meaning in English

常数区域

The constant area type
不断的地区类型
Finally , the two dimensional flow in the diffuser is calculated , the results show that the change of ma makes an effect to the performance of the diffuser . owing to the accretion of ma , the action of oblique shock waves and the boundary layer pricks up , the flow separates from the wall where the shock waves impinge on the boundary layer more quickly , the cluster of diamond shock waves becomes larger . moreover , by comparing the change of flow field under different structure parameter , it is found that the augment of length of constant area section alter the structure of fluid field little , a smaller area ratio and larger angle of compression section make the diffuser working better
最后,针对扩压器中的二维流场进行了数值模拟,结果表明马赫数对扩压器性能影响较大,随着马赫数的增大,扩压器管道内激波-附面层干扰加剧,流动从附面层分离相应加剧,激波串数目增多;通过比较不同结构参数下的扩压器内流场,发现等直段长度的变化几乎没有改变流场结构,只是对局部流场稍有影响,并且在其它参数不变的情况下,一定范围内减小面积比a2 / a1和增大收缩角有利于扩压器性能的提高。