多浮球阻力性能海上实测与数值模拟研究OA北大核心CSTPCD

Floats are the primary buoyancy component of plastic fish cages in offshore aquaculture.They can increase fish cage stress and deformation under the action of sea currents,and the rise of the float's surface liquid level can cause waves on the fish cage walkway.Although plastic fish cages are a recent development in aquaculture,little research has been conducted on the arrangement of floats.Therefore,studying the resistance performance of floats is significant for safe offshore aquaculture production.This article first studies the resistance of single and double floats through on-site measurement methods.Then,based on viscous flow theory,numerical simulations are carried out to simulate the resistance and waveforms of single and double floats under different flow velocities.The simulation results are compared with the on-site measurement results to verify the accuracy of the numerical simulation.Using the same numerical simulation method as above,numerical simulations are carried out for square and diamond two typical float arrangement forms,to analyze liquid level and resistance under different flow velocities.The results show that the numerical model agrees with the on-site measurement results,with an error of 9.5%.Three aspects are used to analyze the advantages and disadvantages of square and diamond arrangements.(1)Liquid level rise:When the flow velocity is the same,the total liquid level rise of the diamond-shaped floats arrangement is less than that of the square arrangement.(2)Flow field distribution in the middle of two floats:The flow field between the two floats of square arrangement is more chaotic than that of diamond arrangement.(3)Average resistance:When the flow velocity is greater than 1.5 m/s,the resistance of diamond arrangement is 29%less than that of square arrangement.The results of the on-site measurement of the small boat towing test are compared with the results of the numerical simulation output.The resistance and waveforms agree with the test results,proving that the numerical simulation method used in this article is accurate and reliable and can provide technical support for subsequent numerical studies of floats.Analyzing the liquid level situation and liquid level cloud images of the two arrangements shows that the diamond arrangement has more stable liquid level changes and better air gap performance than the square arrangement,so it is more suitable for complex offshore environments.The diamond arrangement can provide a better working environment for offshore aquaculture.By sorting out and analyzing the results of numerical simulation,it is found that the average resistance of square arrangement and diamond arrangement is less than that of individual floats.Further comparing average resistance shows that diamond arrangement has less average resistance than square arrangement,so it is more suitable for complex offshore conditions.Floats are the primary buoyancy components of plastic fishing rafts used in offshore aquaculture.Under the influence of sea currents,the resistance generated by floats can result in increased force and deformation of the fishing raft.Additionally,the elevation of the liquid level on the float's surface can induce waves on the raft platform.Therefore,studying the resistance performance of floats is crucial for ensuring the safety of offshore aquaculture production.The resistance performance of both single and double floats was investigated through practical measurements at sea.Numerical simulations based on viscous flow theory were employed to analyze the resistance and waveform of single and double floats at various flow rates.The accuracy of the numerical simulations was validated by comparing the results with actual sea measurements.Furthermore,numerical simulations were conducted to assess the placement of two typical floats in square and diamond configurations.Liquid surface heights and resistance at different flow rates were analyzed.The findings indicate that numerical simulations align well with actual sea measurements,with an error rate of less than 9.5%.The diamond-shaped float configuration corresponds to an elevation in the liquid surface,creating a more stable flow field between the two floats.This results in a smaller average resistance,with values below 29%in flow velocities exceeding 1.5 m/s.Consequently,it is recommended that this placement configuration be adopted for production operations.