目录1.船舶主要要素………………………………………………………12.船体阻力计算………………………………………………………13.船身效率计算………………………………………………………14.收到马力计算………………………………………………………15.假定设计航速有效马力计算………………………………………26.初步确定桨的要素…………………………………………………37.拖力计算……………………………………………………………48.空泡校核……………………………………………………………49.确定螺旋桨的要素…………………………………………………510.强度校核 …………………………………………………………611.确定设计的螺旋桨各切面厚度 …………………………………712.螺距修正 …………………………………………………………813.重量及惯性距计算 ………………………………………………914.螺旋桨计算总结 …………………………………………………915.螺旋桨型值表 ……………………………………………………9MAU型螺旋桨设计计算书1. 船舶主要要素(已知拖网渔船主要参数) 设计水线长 Lwl 46.7m垂线间长 Lpp = 46 m; 型 宽 B = 8.8m; 平均吃水 T = 3.3m; 方形洗漱 cb =0.678 棱形系数 Cp = 0.69; 排水体积 ▽ = 905.7m3排 水 量 △ = 928.3t ;主机功率 MHP = 1400HP;转 速 N = 370r/min;桨轴线中心距基线高 Zp = 1.28m;轴系传递效率 ns =0.97 右旋 材料 铝镍青铜2.船身效率计算根据汉克歇尔公式:伴 流 分 数 ω = 0.77Cp-0.28 =0.2513推力减额分数 t = 0.77Cp-0.3 = 0.2313船 身 效 率 ηH = 1相对旋转效率 ηr = 1 (渔船)4. 收到马力计算 储备功率 10%轴系数效率取 ηS = 0.97收到马力 PD =MHPηSηr= 1222.2HP (公制)5. 假定设计航速有效马力计算序号项目单位数 值1假定设计航速Vs Kn111213142VA=Vs(1-ω)Kn8.2599.7510.53Bp = NPD0.5/VA2.5 66.16953.23043.57736.2074Bp0.58.1347.2966.6016.0175MAU4-40δ91.883.576.870.86P/D0.5880.6120.6360.6637η00.4960.5270.5530.5808THP=PDηHηOηrHp9MAU4-55δ90.382.375.369.310P/D0.630.6550.6820.71011η00.4820.5080.5370.56412THP=PDηHηOηrHp13MAU4-70δ8981.2 74.668.414P/D0.6340.6580.6880.71815η00.4670.4940.5170.54316THP=PDηHηOηrHp根据MAU4-40,MAU4-55,MAU4-70的Bp-δ图谱列下表计算。
据表中的计算结果可绘制THP--Vs曲线,如下图1所示从THP--Vs曲线EHP曲线交点处可获得: MAU4-40 Vs=11.08Kn MAU4-55 Vs=10.95Kn MAU4-70 Vs=10.82Kn图16. 初步确定桨的要素MAU设计航速Vs(kn)P/DδD(m)η04-4010.790.6876.81.520.5554-5510.680.69176.41.550.5384-7010.540.69576.21.600.510以上数据均由上图1查得7. 拖力计算拖网航速Vs=4Kn序号计算项目MAU4-40MAU4-55MAU4-701直径D(m)1.521.551.602VA=0.5145·Vs (1-ω)(m/s)1.651.651.653Q=DHP*75*60/2πN8468468464假定转速N13003403603003403603003403605J=60VA / N1 D0.2170.1920.1810.220.1940.1830.2240.1980.1876K Q =3600Q/ρN1 2 D50.0390.0310.0280.0420.0330.0290.0470.0370.0337J(查图谱)0.1940.1960.2018K Q0.0330.0350.0399K T0.2480.2520.25410N=60·VA /JD33533733511T拖=(Q/D)·(K T / K Q)(kgf)4182406037488.空泡校核根据瓦根宁根限界限线计算桨轴沉深 h s =T M –Z P=2.4m计算温度20°C,则Pv=238kgf/m2取水温20度,Pa-大气压为:10330Kgf/mP0-Pv= P a–P v+hsγ=12552kgf/m2序号项目单位数 值 MAU4-40MAU4-55MAU4-70 1VsKn4442VA = 0.5145 ( 1-ω)Vsm/s1.661.661.663(0.7πND/60)2(m/s)23483433254V0.7R2 = VA2 + (3)(m/s)2350.8345.8327.85σ = (Po-Pv) / 0.5ρV0.7R20.6840.6940.7326τc ( 查瓦根宁根界限线 )0.2340.2450.2557T =(Q/D)·(K T / K Q)kgf4183406137488A p= T /(τc· 0.5ρV0.7R2)m20.970.920.869AE = A p/ (1.067-0.22P/D)m21.0541.0090.94410AE/AD = AE ‘/πD2 /40.5810.5710.5579. 确定螺旋桨的要素据上表计算结果作下图2所示,可求得不发生空泡的最小盘面比以及所对应的最佳螺旋桨要素。
由图可得:AE / A0 =0.56; Vs =10.95Kn ; P / D =0.69 ; D =1.56m ;η0 =0.53N=336r/min,有效拖力Te=T(1-t)=4060*(1-0.173)=3357.62kgf图210. 强度校核根据2001年《钢制海船入籍建造规范》校核t0.25R及t0.6R应不小于按下式计算之值: Y=1.36A1Ne/(ZbN) x=A2GAdN2D3/(1010Zb)计算功率: Ne=Ps×ηS=600×0.97=582 HPD=1.56 m Ad=AE/AO=0.56 P/D=0.69 ε=10o G=7.6 g/cm3 N=336 r/minb0.66R=0.226DAe/Ao/0.1Z=0.479b0.25R=0.722b0.66R=0.346 b0.6R=0.9911b0.66R=0.478项 目数 值0.25R0.6R舷长 b0.3460.478k1634207k2250151k31410635k4434A1=D/P(k1-k2D/P0.7R)+k3D/P0.7R-k42490.2886.5Y=A1Ne/ZbN3107.3800.7k58223k63412k74165k8380330A2=D/P(k5+k6ε)+k7ε+k81419.81193.4材料系数K(锰铁黄铜)11x=A2GAdN2D3/(1010Zb)0.1660.102t=[Y/(k-x)]0.561.035.0AU标准桨厚度t’60.536.17校核结果不满足要求满足要求实取桨叶厚度613511.确定设计的螺旋桨各切面厚度实际桨叶厚度按t1.0R=0.003D=5.0 mm 与t0.25R=61.2 mm连成直线决定:图三。
从图中可得出各切面最大厚度为:t0.2R=64mm t0.3R=57mm t0.4R=49mm t0.5R=42mmt0.6R=35mm t0.7R=27mm t0.8R=21mm t0.9R=14mm图312.螺距修正由于实际桨叶厚度小于标准厚度,故需因厚度差异进行螺距修正设计桨 (t/b)0.7R=0.027/0.9964b0.66R =0.055标准桨 (t/b)’0.7R=0.0171D/(0.9964×0.31075D)=0.055231- s=Va/Np=(1-w)*V*30.866/Np=0.8089Δ(t/b)0.7R=[(t/b)0.7R设-(t/b)0.7R标*0.55/0.544]*0.75=0.000556Δ(t/b)t= -2(P/D)0*(1-S) *Δ(t/b)0.7R=-2*0.67*0.8089*0.000556=-0.000603修正后的螺距比为:P/D=(P/D)0+Δ(t/b)。