P0 0.1 "源压力幅值"
beta 1 "非线性系数"
N 5 "要解析的谐波数"
r0 1 "内半径"
r_sh "r0*(1 + 1/(4*pi*beta*P0*r0))^2" "激波形成半径"
a 0.7 "相对冲击距离"
tau 0 "延迟时间"