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介绍了进行敏感度导数计算的有限差分法和复变量法。在原有流场求解程序的基础上,引入了复变量,实现了敏感度导数的自动计算。算例验证表明,差分法由于减消误差(subtractive cancellation error)的存在,其计算精度对扰动步长比较敏感,合适的扰动步长需经过多次尝试才能得到。而复变量方法虽然计算量大,但是由于没有引入减消误差,因而当扰动步长趋于足够小时其计算精度能够真正达到二阶精度。
The finite difference method and complex variable method are introduced to calculate the sensitivity derivative. Based on the original flow solver, the complex variable is introduced to realize the automatic calculation of the sensitivity derivative. Numerical examples show that the accuracy of the difference method is sensitive to the disturbance step due to the existence of subtractive cancellation error, and the appropriate disturbance step can only be obtained after many attempts. Although the complex variable method is computationally intensive, the accuracy of second order accuracy can be truly reached when the perturbation step tends to be small enough because no cancellation error is introduced.