郭真祥臺灣大學：工程科學及海洋工程學研究所Chen, Yen-JenYen-JenChen2007-11-262018-06-282007-11-262018-06-282004http://ntur.lib.ntu.edu.tw//handle/246246/51062In the present thesis, the computational fluid dynamics method is applied to study the scale effect problem of the form factor. In this method, the turbulent flow around ship hull is analyzed by solving the Reynolds-averaged Navier-Stoke equation using the finite volume method. The space parallelism and a PC-cluster with 16 nodes are employed to speed up the computations. First, the applied method is verified at model-scale by comparing the calculated results with the measured data from the model tests. The grid dependency problem is studied by refining the grids systematically. It improves the reliability of the numerical approach and makes that the present method has the ability to predict the ship flow. The prediction is verified using the model test which is performed subsequently. Moreover, the full-scale ship flow is also computed and compared to the model-scale ship flow in this thesis. The resistance predictions at full-scale are indirectly verified through the qualitative comparisons of the important flow properties at different scales. In the last part of the present thesis, the resistance of several kinds of surface ship and sub-body are computed at different Reynolds numbers. By comparing the calculated results in this thesis, the scale effect problems of the form factor are discussed. Reviewing all calculated results, a unique trend among all hull forms is observed in the specific range of Reynolds number. As Reynolds number increases, the ratio of the pressure term to the total resistance increases, and the form factor also increases slightly.1. Introduction 1 1.1. Form Factor and Scale Effect 1 1.2. CFD in Ship Resistance Prediction 2 1.3. Researches of Scale Effect Problem 4 1.4. Focal Points of the Present Thesis 6 2. Applied Method 9 2.1. Governing Equations 9 2.2. Turbulence Modeling 11 2.3. Numerical Method 14 2.3.1. Finite Volume Method 14 2.3.2. Calculation of Pressure 14 2.3.3. Free-Surface Treatment 15 2.3.4. Wall Function 16 2.3.5. Blending Factor 17 2.3.6. CFD Solver 17 2.4. Computational Space and Boundary Condition 18 2.5. Parallel Processing 20 2.6. PC-Cluster 22 2.6.1. Initial Configuration 22 2.6.2. Bottleneck of Parallelization Efficiency 22 2.6.3. Benchmark of the PC-Cluster 23 3. Verification of Model-Scale Ship Flow 27 3.1. Verification of Simplified Hull Form 28 3.2. Verification of Practical Hull Form 32 3.2.1. Case Description 32 3.2.2. Arrangement of Numerical Grids 33 3.2.3. Verification of Total Resistance 34 3.2.4. Verification of Free-Surface Wave System 35 3.2.5. Verification of Wake Distribution 40 3.3. Assessment of Efficient Grid Arrangement 42 3.3.1. Grid Dependency 42 3.3.2. Systematic Grid Refinement 42 3.3.3. Grid Dependency on Free-Surface Waves 44 3.3.4. Grid Dependency on Wake Distribution 49 3.4. Preliminary Test of k-ω Model 55 3.5. Test of Predicting Capability 56 3.5.1. Case Description 56 3.5.2. Verification of Resistance 57 3.5.3. Verification of Wake at Propeller Plane 60 3.5.4. Re-Computations using Standard k-1881245 bytesapplication/pdfen-US網格影響船舶阻力形狀因子計算流體力學尺度效應Computational Fluid DynForm FactorScale Effectthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/51062/1/ntu-93-D88525001-1.pdf