Simulation Of Influences On Distribution Of Electromagnetic Field In Single Mode Sintering Cavity By HFSS

Microwave heating technique has attracted more and more attention of researchers in recent years,especially in the field of microwave sintering of ceramics.Due to simple structure,easy being controlled and regulated and other advantages,single mode sintering cavity has been widely used,among which the TE₁₀₃ is the most typical one.It is important to know the optimal cavity length based on resonant property of cavity that provides prerequisite for distribution of electrical field(E-field).And the research on different geometries and microwave properties contributes to higher pertinence of microwave sintering.Practically,the analytic method can only solve simple cavity model rather than complex geometrical cavity or cavity loaded with sample.Therefore,the electromagnetic simulation software based on numerical method becomes the best choice.Ansoft HFSS is a three-dimensional electromagnetic simulation software based on finite element method(FEM).In this thesis,two types of TE₁₀₃ single mode cavity models—BJ-22 and improved cavity were built(proposed) to simulate resonant property and distribution contour of electromagnetic field(EM-field) by using HFSS software.And homogeneous E-field regions were identified respectively.The results show improved cavity extends the range of homogeneous regions in the direction of broad wall.The different influential factors in modeling were analyzed to show deviation in frequency decreases the homogeneous region and usage of 2D and symmetric faces can reduce time and resources.The contour of E-field in cavity loaded with cylindrical sample was simulated.The simulation shows three homogeneous E-field regions contracts with middle region contracting lager than both-sides. The influences of different physical dimensions and microwave properties on distribution of E-field were discussed with parameter sweeping.The results show E-field in sample becomes bigger from inner to exterior with shorter radius(R).The bigger E-field appears in center and both sides of sample with bigger R.Different height(H) and relative permittivity(ε_r) lead to converse distribution of E-field.E-field in sample inclines to reach uniformity when H orε_r reaches a specific value.The decrement of horizontal depolarization field is greater than the increment of vertical depolarization field with H increasing.The depolarization field enhances withε_r increasing.The distribution of E-field in sample always becomes bigger gradually from inner to exterior as dielectric loss angle tangent(tgδ) changes.But distribution of E-field in cavity keeps the same as tgδchanges.The depolarization field of sample grows slowly with tgδincreasing.