叶弦 meaning in English

blade chord
chord of a foil
chord of foil

The blade section can be designed by parent section , thereby its chordwis circulation distributions can be worked out , and then lifting surface theory is used to design the three dimension blade geometry
剖面采用母型剖面方法来设计，进而可确定桨叶弦向环量分布，然后由升力面理论设计三维桨叶的几何形状。
The theoretical deduction in chapter 3 shows that the shape of load distribution used in the arithmetic is a decisive fact of the error margin size , the more the adoptive shape looks like the actual case , the smaller the error margin will be , therefore the tilt parabola shape can instead of the actual shape of load distribution in the permissible error margin when we predicting constant loading noise caused by the tail rotor of helicopter
在第三章中通过理论推导和计算比较发现,在预测直升机尾桨定常载荷噪声时,其误差大小取决于算法中桨叶弦向载荷分布的数学描述与实际弦向载荷分布的吻合程度,而选取一种与实际弦向载荷分布较为相似的斜抛物线形来预测噪声所导致的误差是很小的。