柴油机磁场的计算、试验与消磁优化

为研究低磁船舶的柴油机磁性及消磁问题，通过柴油机磁场有限元仿真的计算结果来指导消磁工作。利用磁场分析Comsol软件，建立某型柴油机有限元仿真模型，进行地磁场作用下柴油机产生感应磁场及其空间分布的相关计算。引入磁铁抵消消磁法，通过柴油机和消磁磁阵的一体化仿真，进行优化计算，找到最佳消磁参数。结果表明：柴油机下方9 m平面上，正中心位置磁通密度最大，磁场呈椭圆形分布，磁场强度相对地磁场最大畸变量计算值高达224.35 nT，将测量结果与仿真计算结果进行对比，误差不超过5%，在允许的误差范围内；最佳消磁参数可以使柴油机下方9 m平面上的磁场强度畸变量降低至8.33 nT，降低约95%.

CalculationTest and Degaussing Optimization of Magnetic Field in Diesel Engine

The magnetism and demagnetization of diesel engine of low magnetic ship are studied from the finite element simulation results of magnetic field of diesel engine. A finite element simulation model of a diesel engine is established by using the magnetic analysis COMSOL software, and the strength of induced magnetic field and its spatial distribution are calculated. The degaussing method is used to find the optimal degaussing parameters through the integrated simulation of the diesel engine and degaussing array. The results show that, on a plane at 9 m below the diesel engine, the magnetic flux density at the positive center is the largest, the magnetic field is elliptically distributed, and the calculated value of the magnetic field strength relative to the maximum distortion of the geomagnetic field is as high as 224.35 NT. The error between the measured result and the simulated result is less than 5%, within the allowable error range; the optimal degaussing parameters can be used to reduce the intensity distortion variable of magnetic field on the plane at 9 m below the diesel engine to 8.33 nT, about 95%. Key