Study on Transom Stern Form Design Method Based on a New Theory

1.横尾底廓形式对尾波阻力的影响(1)横尾底廓形式的影响：在较低船速范围F_<rI><3.1时，凹形的尾波阻力最小。在较高的航速范围F_<rI>>3.1时，平坦的尾波轮廓产生的尾波阻力最小。(2)尾底廓形式与尾波阻力的关系：—在较低船速范围F_<rI><3.1时，尾底廓形式主要通过控制实际尾浸水I_r来控制尾波阻力。-在F_<rI>>3.1较高航速范围内，尾底剖面形式主要通过控制剩余的尾随波高来控制尾波阻力。-在较低的船速范围内，凹形的船尾底部轮廓导致最小的实际船尾浸入I_r。平坦的船尾底部轮廓导致了最低的剩余跟随波高，这在更高的船速范围内是很重要的。(3)对船体阻力影响的相对量：对全尺寸船舶来说，船尾底部形状变化的影响量估计是显著的。(1)建立了一种估算实际船尾浸没对船尾波阻力影响的方法。本文提出了一种考虑实际船尾浸没对船尾波阻力影响的解析估算方法。在该方法中，尾波阻力被视为由四部分组成：由于swbf的阻力，由于rfw的阻力，由于尾端水流加速的阻力和由于尾端平面静水压变化的阻力。(2)铁对尾波阻力影响的详细情况用上述方法对模型试验结果进行分析，明确了以下几点：-I_r通过影响尾端水流速度和尾波高2_< 0>与尾波阻力有关。-在F_<rI><3.1的下弗鲁德数范围内，I_r/I较大。I_r/I越大，由于尾端水流加速，阻力越大C_<accs>, C_<accs>占尾波阻力C_<sw>的比重越大。I_r/I主要通过C_<accs>影响尾波阻力C_<sw>，因此尾波阻力几乎由F_<rI>和I_r/I决定。-在F_<rI>>3.1的较高弗鲁德数范围内，I_r/I较小。因此，I_r/I对尾浪阻力的影响并不重要。尾波阻力主要是由于rfw C_<sfw>引起的阻力，因此尾波阻力几乎由F_<rI>和θ_e.3决定。基于上述研究结果，本文提出了一种适用于超吃水范围船舶（如集装箱船）的横尾底廓形设计的理论方法。从现在开始的研究计划我们想研究这样一种尾波阻力等于0的横尾形式。这种尾梁形式具有重要的实际意义，也是研究尾梁形式的必要条件，因为使用尾梁形式可以将尾波阻力与残余阻力隔离开来。少

1.Effect of Transom Stern Bottom Profile Form on Stern Wave Resistance(1)Effect of the transom stern bottom profile form:The concave stern bottom profile causes the lowest stern wave resistance at the lower ship speed range of F_<rI><3.1. The flat stern bottom profile causes the smallest stern wave resistance at the higher ship speed range of F_<rI>>3.1.(2)Relation between Stern Bottom Profile Form and Stern Wave Resistance:-At the lower ship speed rage of F_<rI><3.1, the stern bottom profile form controls the stern wave resistance mainly by controlling the real stern end immersion I_r.-At the higher ship speed range of F_<rI>>3.1, the stern bottom profile form controls the stern wave resistance mainly by controlling the remaining following wave height.-The concave stern bottom profile causes the smallest real stern end immersion I_r which is important at the lower ship speed range. The flat stern bottom profile causes the lowest remaining following wave height which is important at th … More e higher ship speed range.(3)Relative amount of the effect in hull resistance:Amount of the effect of the stern bottom form change is estimated to be significant in the powering for a full-scale ship.2.Effect of I_r(stern end immersion at running) on Stern Wave Resistance(1)Development of a method to estimate the effect of real stern immersion I_r on the stern wave resistance-An analytical method to estimate the stern wave resistance due to a transom stern taking I_r into consideration has been developed.-In the method, the stern wave resistance is treated as consisting of the four components : that due to the swbf, that due to the rfw, that due to acceleration of water flow at the stern end and that due to static water pressure change on the stern end plane.(2)Details of the effect of Iron the stern wave resistanceAnalysis of the model test results with above developed method has clarified the followings:-I_r relates with the stern wave resistance through its affecting the water flow velocity at the stern end viand the stern wave height 2_<r0>.-At the lower Froude number range of F_<rI><3.1:I_r/I is larger. The larger I_r/I brings larger resistance due to acceleration of water flow at the stern end C_<accs> and the C_<accs> occupies larger part of the stern wave resistance C_<sw>. I_r/I affects the stern wave resistance C_<sw> mainly through the C_<accs> The stern wave resistance is, therefore, almost decided by F_<rI> and I_r/I.-At the higher Froude number range of F_<rI>>3.1:I_r/I is smaller. The effect of I_r/I on the stern wave resistance is, therefore, not important. The stern wave resistance, the main part of which is the resistance due to the rfw C_<sfw>, is accordingly almost decided by F_<rI> and θ_e.3.Development of a Transom Stern Bottom Profile Form Design MethodBased on the results of the study described above, an theoretical method to design bottom profile form of the transom stern for such a ship that runs over a range of draft as a container ship has been proposed.4.Study Plan from NowWe would like to study on such a transom stern form of which stern wave resistance is equal to 0. Such a transom stern form is practically important and also necessary for study of transom stern form, because the stern wave resistance can be isolated from the residual resistance by using the transom stern form. Less