The Ship Launching Experiment Research Under Icy Condition

It is a technical process to move ships from the building region to water area. The slipway studied in the paper is a semi-submersible types of longitudinal slipway, to be different from the groovy longitudinal launching process, the ship launching has not the first free glide stage, the initial velocity is low, and maybe happened under icy condition according to the building procedure, it may launch at the icing time. However, it does not make the problem of launching at icing time into account. In order to protect the rudder and oar from the ice loading, the ice educed fitting should be set at the tail of ships. For the exist of the ice educed fitting and ice loading, the launching drag gets increased, and it may cause the trouble to make the ship stop on the slipway. For the sake of validating or adopting proper measure to ensure the ship launch successfully, and designing the fitting reasonably, it is very necessary to elaborately study the problem on launching under the ice condition. By now, there has been any one to get down to the research of shipping launching under the ice condition, specially, the method of model experiment and the manufacture technology of large-scale model ice are all new question for study.All main contents of study in the paper were based on the project, the experimental research of ice-educed fitting for a launching slipway under ice condition. A oil tanker and a semi-submersible gradient slipway are the object, and the method of model experiment was adopted to study the problem of launching under ice condition.Firstly, there was much early work to be done, including similitude analysis for model experiment under ice condition, the certainty of experimental method, the discussion for manufacture technology of model and the testing measure of model ice intensity. Secondly, according to the launching state of a ship , and the concrete data of shipway, the models were designed, for example, the shipping model, shipway model, ice-educed plate and ice model etc. Lastly, the experiment project got optimized, and the methods of measure and dealing with data were deeply studied. In the paper, the model experiments for six ice-educed plate designed were carried out at three tidewater position under ice and no-ice condition. As a result, the moving law and the force of ice-educed plate were analyzed. In terms of the analysis to experimental data, better ice-educed plate was choosed, the ice and hydrodynamic loadings of ice-educed plate were gained to supply data for the design of ice-educed plate. Based on the research above, the mathematics model of shipping launching movement was developed, and the emulational soft of shipping launching with VC and OpenGL programme was empoldered. The results were consistent between simulation and experiment. The results of model experiment and simulation can be applied in the practical production of dockyard, and there will be important significance for the reference and direction to further study on shipping launching under ice condition.