Finite element analysis of high field permanent magnet mechanism using vector Preisach hysteresis model
This paper presents a method to simulate abnormal magnetizations in high field permanent magnet mechanism. Abnormal magnetizations including local saturation, local demagnetization and rotational magnetization occur in the assembly process of high field permanent magnet mechanism. Combining an anisotropic vector Preisach model and finite element analysis, abnormal magnetizations are simulated comprehensively. The method only requires the data of limiting magnetic hysteresis loops of the material along easy and hard axis, so the application of vector Preisach model becomes convenient and efficient. A sixteen elements enhanced magic ring is designed and the process of assembling is simulated, which verify the validity of the presented method.
Finite Element Analysis of Permanent Magnet Assembly with High Field Strength Using Preisach Theory
This paper presents a finite element analysis combined with an improved Preisach model to implement the dynamic simulation of permanent magnet assembly under direction-varying high field
Numerical and experimental investigation on air distributor design of fluidized bed reactor of sawdust pyrolysis
Abstract An improved biomass conversion in a lab-scale fluidized bed reactor (FBR) is achieved by optimizing the air distributor orifice size and number. Two approaches for introducing air were numerically and experimentally examined. These included perforated plate and downward orifice sparger. 3 mm and 5 mm orifice diameters, and 7, 9 and 13 holes were simulated at flow velocities of 2, 4, 6, and 8 times the minimum fluidization velocity, Umf. The simulation results revealed that increasing the orifice number has a positive effect on gas holdup, particularly for the perforated plate, which showed a uniform distribution of bubbles. The sparger configuration produced larger bubbles sizes, which could lead to better recirculation of solid flux, while stagnant particle zones were observed at the lower section of both distributors. A pyrolysis unit is also inserted at the top of freeboard of the FBR. For perforated plate with 6Umf, the pyrolysis process achieved thermal and cold gas efficiencies of 82.91% and 52.03%, respectively, while combustible gases with 41.6%mol CO, 8.7%mol CH 4 and 2.17%mol HC, were obtained. For sparger pipe and 6U mf _sp, 35.33 ppm NOx and 111 ppm SO 2 were measured in flue gas from combustion process at bed region.