Concept Design Of M Channel Planning Craft

M channel planning craft has excellent hydrodynamic performance and wide applicationprospect. Double M channel planning craft Stiletto is assessed as “the best invention in2006”by Time magazine. Domestic research on M channel planning craft is still in initial stage andthus related material is relatively scarce. In this thesis, concept design has been done for Mchannel planning craft, and it’s a positive and meaningful attempt with reference value forsubsequent research.The main contents of this paper include:1.Selecting principal dimensions for M channel planning craft through comparinganalysis, building up3D model with Solidworks software and drawing molded lines based onMaxsurf output.Design of molded lines is a cyclic process, namely building3D model in Solidworkssoftware according to primitive molded lines, exporting the3D model to Maxsurf software tocheck the molded lines produced by it, then modifying molded lines in AutoCAD softwareand finally return to the starting point to build the3D model with new molded lines until asatisfactory result.2.General performance analysis based on Maxsurf, including hull speed, seakeepingperformance and stability.In this thesis, the author has adopted semi-empirical and semi-theoretical formula andMaxsurf software to calculate the resistance of M channel planning craft. Relatedsemi-empirical and semi-theoretical formula for calculation of planning craft resistancemainly include SIT and “ЦАГИ” method etc among which SIT is applied wider, and thus inthis thesis SIT method is adopted. Calculation results show that semi-empirical andsemi-theoretical formula result matches well with Maxsurf software calculation result and itproves that M channel planning craft possesses good speediness by compared with parent shipAs for seakeeping performance analysis, the author adopts spectrum analysis methodbased on Maxsurf software. Selected spectrums are P-M and ITTC two parameter spectrum.Parameters of wave are set according to level4sea condition, including significant waveheight and average period. Maxsurf software calculation results show that planning craft’sseakeeping performance in pitch amplitude and heave amplitude is acceptable whileseakeeping performance in heave acceleration and heel amplitude is quite not satisfactory. Therefore, in this thesis, the author has analyzed the reasons and put forward some solutionsfor this problem.Ship stability refers to the ability of recovering to equilibrium position after heel due toloads. In this thesis, the author has applied Hydromax to analyze stability of the planning craftunder departure and arrival work conditions, including hydrostatic curves drawing, floatingstatus check and large angle stability check with HSC criteria. Hydromax software calculationresults show that the planning craft possess enough stability under departure and arrivalconditions even with wind pressure.3. Rule structure design using DNV rulesStructure rule calculation is based on DNV 《RULES FOR CLASSIFICATION OFHIGH SPEED, LIGHT CRAFT AND NAVAL SURFACE CRAFT》（2012.4）.Plate thicknessand stiffener section modulus are dependent on sea pressure and wave slamming loadscalculated before.4.Finite Element Analysis for M channel planning craft based on ANSYS Workbench,including strength check and modal analysis.Strength analysis and modal analysis have been conducted in this thesis based onANSYS Workbench software. Engine room structure is selected as analysis target is due tofollowing reasons. Firstly, engine room structure has been proved to assume the largest totalload in DNV rule calculation, including sea pressure and slamming load, and thereforestrength analysis of engine room structure is quite necessary since other structure will surelylive up to strength standards if engine room structure does. Secondly, engine room structureassumes vibration forces due to main engine and shaft vibration, and wave slamming load atthe same time. The dynamic analysis of it is much more complex than other structures, so it’sessential to conduct modal analysis for it alone to master the characteristics of vibrationmodes and inherent frequencies.ANSYS Workbench software calculation results show that engine room structure hasenough strength and little deformation, which is satisfactory. In this thesis, the author hasgiven total deformation of six order modal analysis and inherent frequency, which can beviewed as reference materials for subsequent dynamic analysis.