编写Fluent的udf来描述鱼类游动的运动方程，方程为h(x,t)=a(x)sin(kx-wt),a(x)=a0+a1x+a2x^2,a0=0.02,a1=-0.08,a2=0.16，k=2pi/q,q=0.95,w=2*pi*f,具体描述见文献[1]J Liu, H Hu. Biological inspiration: From Carangiform fish to multi-joint robotic fish[J]. Journal of Bionic Engineering, 2