变径管计算

锥形钢管下底半径是630，上面半径是508，圆管壁厚是70，长970.欲算其体积，
Φ630~Φ508Φ应该表示的是直径，问题补充的不正确哦按直径计算：
外圆台上底半径R1=0.508/2=0.254m
外圆台下底半径R2=0.63/2=0.315
壁厚0.07
内圆台上底半径r1=0.254-0.07=0.184
外圆台下底半径r2=0.315-0.07=0.245
体积V=V外-V内=1/3πH(R1^2+R2^2+R1R2)-1/3πH(r1^2+r2^2+r1r2)
=1/3πH[ (R1^2-r1^2) + (R2^2-r2^2) + (R1R2-r1r2)]
=1/3 * 3.1416 * 0.97 *[ (0.254^2-0.184^2) + (0.315^2-0.245^2) + (0.254*0.315-0.184*0.245)]
=1/3 * 3.1416 * 0.97 *[ (0.254^2-0.184^2) + (0.315^2-0.245^2) + (0.254*0.315-0.184*0.245)]
≈ 1.016 *（0.031+0.039+0.035）
≈ 1.016 *0.105≈ 0.107m^3