Abstract

In order to accurately predict the erosion effect of underwater cleaning with an angle nozzle under different working conditions, this paper uses refractory bricks to simulate marine fouling as the erosion target, and studies the optimized erosion prediction model by erosion test based on the submerged low-pressure water jet. The erosion test is conducted by orthogonal experimental design, and experimental data are used for the prediction model. By combining with statistical range and variance analysis methods, the jet pressure, impact time and jet angle are determined as three inputs of the prediction model, and erosion depth is the output index of the prediction model. A virtual data generation method is used to increase the amount of input data for the prediction model. This paper also proposes a Mind-evolved Advanced Genetic Algorithm (MAGA), which has a reliable optimization effect in the verification of four stand test functions. Then, the improved back-propagating (BP) neural network prediction models are established by respectively using Genetic Algorithm (GA) and MAGA optimization algorithms to optimize the initial thresholds and weights of the BP neural network. Compared to the prediction results of the BP and GA-BP models, the R2 of the MAGA-BP model is the highest, reaching 0.9954; the total error is reduced by 47.31% and 35.01%; the root mean square error decreases by 51.05% and 31.80%; and the maximum absolute percentage error decreases by 65.79% and 64.01%, respectively. The average prediction accuracy of the MAGA-BP model is controlled within 3%, which has been significantly improved. The results show that the prediction accuracy of the MAGA-BP prediction model is higher and more reliable, and the MAGA algorithm has a good optimization effect. This optimized erosion prediction method is feasible.

Highlights

  • Marine fouling is a serious problem in ship operations

  • The optimized erosion prediction method can be applied to the formulation and control of the hull underwater cleaning scheme, which is an important part of the ship hull underwater cleaning robot project

  • The prediction results of the Mind-evolved Advanced Genetic Algorithm (MAGA)-BP model are closer to the points of experimental values

Read more

Summary

Introduction

Marine fouling is a serious problem in ship operations. The marine fouling adhering to the hull can increase navigation resistance and fuel consumption, up to 40% [1]. Submerged cavitation water jet technology is one of the cleaning methods that can be applied in the underwater cleaning of the ship hull. The high-speed water jet formed by the nozzle under water interacts with the low-speed water of the surrounding medium, generating strong disturbances, and forming periodic vortex rings on the periphery of the jet. Both the low-pressure region of the vortex center

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call