Multi-Field Coupling Simulation Analysis And Noise Reduction Design Of Electromagnetic Noise In Induction Cooker

As a representative of the modern kitchen revolution,the induction cooker has the characteristics of no open flame,high thermal efficiency,safety,environmental protection,and easy cleaning,so it is favored by consumers.However,electromagnetic vibration is inevitable,which generates noise.In this paper,the induction cooker is taken as the research object.The mechanism of electromagnetic noise and the method of multi-field coupling simulation is analyzed,and the improved scheme of reducing electromagnetic noise is proposed.It is expected to provide a theoretical basis for the design and optimization of induction cooker products.The specific research content of the paper is arranged as follows:(1)Analysis of electromagnetic field and electromagnetic force of the induction cooker.According to the basic working principle of the induction cooker,the electromagnetic force includes the Lorentz force caused by the eddy current and the Kelvin force generated by the magnetization of the pot.Theoretically,the performance characteristics and influencing factors of Lorentz force and Kelvin force are analyzed.The electromagnetic field and electromagnetic force of the induction cooker are simulated by Maxwell to verify the theoretical analysis conclusion,and the simulation results will be used as the excitation of multiphysics coupling simulation.(2)Analysis of wet modal of pots.Explain the experimental principle and test process of the modal,and test the wet modal of the pot with the hammer method.Contrast simulation principle and application range of fluid-solid coupling method,liquid slosh equivalent mechanical model method,acoustic-solid coupling method.Through the workbench modal analysis module,the acoustic-solid coupling method is used to predict the wet modal of the pot.The prediction results are in good agreement with the experimental results.Through the comparison of the simulation results under different water content,the influence of the water content of the pot on the modal frequency is analyzed.(3)Research on multi-field coupling simulation method of electromagnetic vibration and noise.Since electromagnetic vibration noise involves many physical phenomena,such as electromagnetic induction,structural vibration,and gas fluctuation,so its simulation requires electromagnetic field,structure field,flow field and sound field to be coupled with each other.Through the analysis of variate coupling and data transfer between different physics fields,a multiphysics coupling simulation system consisting of Maxwell,Transient Structural,Fluent,System Coupling and other modules is built on the workbench platform to predict the electromagnetic noise.Compared with the noise experiment results,the error between the prediction results and the experimental results does not exceed 7%.(4)Noise reduction design of induction cooker.Analyze the method of electromagnetic noise reduction design from both active and passive aspects and the heating principle of induction cooker.Based on the influence of conductivity,permeability,thickness of the pot,thickness and distribution of magnetic strip on electromagnetic force and thermal power,an active noise reduction scheme is proposed.Under the premise of ensuring the heating efficiency of the induction cooker,the electromagnetic force amplitude is reduced.Thereby,the active noise reduction of electromagnetic noise is realized.The noise reduction scheme is verified by multi-physics coupling simulation.Since the pot and the panel are vibration sources that cause electromagnetic noise of the induction cooker,it is considered to increase the stiffness of the panel to reduce the vibration amplitude under the electromagnetic force excitation,which realizes passive noise reduction of electromagnetic noise.