The Bottom Design And Drag-reduction Property Research Of H-yacht

High-speed boat, also known as high-performance boat, is the hot spot of worldyacht industry development and the research. High-performance boat owescharacteristics of high speed, shallow draft, seakeeper, amphibian, so designing anddeveloping new high-speed boat will be a long-term research direction in the future.H-drag reduction boat belonging to high-speed boats, mainly used air lubricationto reduce the resistance. H-boat consists of main hull, two wide sheet bodies, deck andknuckleline. In the middle, it’s the narrow channel. The sides of the hull have ashallow channel. When the boat is speeding fast, sleigh-style bow makes a lot of airinto the bottom. With increasing speed, the air pressure increasing, a high-pressure aircushion is formed, the hull is lifted up by aerodynamic lift power. Through reducingthe wet surface area of the hull, reducing water friction on the hull, the speed of theship’s voyage is improved.Using MAXSURF software, the resistance of the hull, effective horsepower,hydrodynamic performance and seakeeper are analyzed, and the basic performance ofthe hull is obtained.Using CFD numerical simulation software FLUENT, water and gas two-phaseflow is simulated, the basic properties of H-boat sailing are obtained. By analyzing thedynamic pressure, hydrostatic pressure, moisture distribution and oscillogram atdifferent speed, the resistance is observed. By comparing simulation number valuewith frictional resistance value got from empirical formula, the characteristics of theresistance forecasting in both are analyzed. By numerical simulation, we can get apreliminary understanding of the ship’s route and resistance, which can provide aneffective basis for improving and optimizing the ship-form.Based on the micro-circulating pool experimental data, ship model resistance values were obtained under different speeds. By comparing the numerical simulationvalue with the pool experimental value, their characteristics to obtain resistance wereanalyzed.Through the analysis we can draw the following conclusion:1、Numerical simulation has certain accuracy in predicting hull resistance.2、Hull structure design can meet the low resistance performance at high speed.3、By moisture distribution, dynamic and static pressure figure, oscillograph andresistance values, we can analyze that when the volume Froude number1<Fr <3, thehull is over type, splashing phenomenon exists. When speed is14.3m above, the hullvolume Froude numberFr>3, the boat is gliding state, most of the hull out of thewater, then the resistance began to decline. At the same time, as the hull is sliding state,the wave resistance is greatly reduced.4、Micro-circulating pool ship model experiment have changed the shortcomings oftraditional pools’ covering large area, which can provide effective data for resistanceforecasts of the real ship.