D 5[mm] "主管道直径"
L 4*D "主管道长度"
alpha 45[deg] "换能器管道倾角"
D_transducer 2[mm] "换能器直径"
L_transducer D/cos(alpha)+3/2*D_transducer/cos(alpha)*tan(alpha) "换能器管道长度"
L2 D/sin(alpha) "主流中的换能器管道长度"
L1 0.5*(L_transducer-L2) "支流中的换能器管道长度"
L_matching cp_match/f0/4 "匹配层厚度"
L_piezo cp_pzt/f0/2 "压电换能器厚度"
nLx cos(alpha) "换能器管道方向的单位矢量（x 分量）"
nLy 0 "换能器管道方向的单位矢量（y 分量）"
nLz sin(alpha) "换能器管道方向的单位矢量（z 分量）"