In this paper, an autonomous orbit determination method for satellite using a large field of view star sensor is presented. The simulation of orbit under atmospheric drag perturbation are given with expanded Kalman fi...In this paper, an autonomous orbit determination method for satellite using a large field of view star sensor is presented. The simulation of orbit under atmospheric drag perturbation are given with expanded Kalman filtering. The large field of view star sensor has the same precision as star sensor and a sufficient filed of view. Therefore ,the refraction stars can be observed more accurately in real time. The geometric relation between the refracted starlight and the earth can be determined by tangent altitude of the refraction starlight. And then the earth center can be determined in satellite body frame. The simulation shows that the precision of the mean square deviation of satellite’s position and velocity is 5m and 0.01m/s respectively. The calculated decrement of the semi-major axis in one day is close to the theoretical result, and the absolute error is in the range of decimeter when the altitude of orbit is 750 km. The simu- lateion of orbit of different initial semi-major axis shows that the higher the altitude of orbit is, the smaller the dec- rement of the semi-major axis is, and when the altitude of orbit is 1700 km the decimeter of the semi-major axis is 10-7 km.展开更多
固相亚格子尺度过滤模型是在高精度的网格下,系统地过滤了基于结合颗粒动理学的双流体模型的模拟结果而得到的曳力和固相应力等本构关系的计算模型。今分别采用固相亚格子尺度过滤模型(Filtered Model I)、壁面修正固相亚格子尺度过滤模...固相亚格子尺度过滤模型是在高精度的网格下,系统地过滤了基于结合颗粒动理学的双流体模型的模拟结果而得到的曳力和固相应力等本构关系的计算模型。今分别采用固相亚格子尺度过滤模型(Filtered Model I)、壁面修正固相亚格子尺度过滤模型(Filtered Model II)和改进的固相亚格子尺度过滤模型(Filtered Model III)模拟NETL/PSRI挑战问题中的提升管内的颗粒流动特性,得到了时均气体压力梯度和时均轴向颗粒速度等分布。亚格子尺度模型和均匀流动模型(Huilin-Gidaspow model)的研究结果相比,改进的固相亚格子尺度过滤模型(Filtered Model III)与实验值更接近,尤其是对于高颗粒浓度流动。壁面修正可以提高压力梯度,从时均轴向颗粒速度分布曲线,可以看出在提升管内颗粒流动结构呈现更为明显的环核流动结构;同时,研究了提升管内气体压缩性、壁面修正和计算网格对模拟结果的影响,分析表明气体的可压缩性对提升管内轴向气体压力梯度有影响,在模拟计算时考虑气体的压缩性,可以提高计算精度。展开更多
基金Project CXJJ-84 supported by Science and Technology Innovation Foundation of Chinese Academy of Science
文摘In this paper, an autonomous orbit determination method for satellite using a large field of view star sensor is presented. The simulation of orbit under atmospheric drag perturbation are given with expanded Kalman filtering. The large field of view star sensor has the same precision as star sensor and a sufficient filed of view. Therefore ,the refraction stars can be observed more accurately in real time. The geometric relation between the refracted starlight and the earth can be determined by tangent altitude of the refraction starlight. And then the earth center can be determined in satellite body frame. The simulation shows that the precision of the mean square deviation of satellite’s position and velocity is 5m and 0.01m/s respectively. The calculated decrement of the semi-major axis in one day is close to the theoretical result, and the absolute error is in the range of decimeter when the altitude of orbit is 750 km. The simu- lateion of orbit of different initial semi-major axis shows that the higher the altitude of orbit is, the smaller the dec- rement of the semi-major axis is, and when the altitude of orbit is 1700 km the decimeter of the semi-major axis is 10-7 km.
文摘固相亚格子尺度过滤模型是在高精度的网格下,系统地过滤了基于结合颗粒动理学的双流体模型的模拟结果而得到的曳力和固相应力等本构关系的计算模型。今分别采用固相亚格子尺度过滤模型(Filtered Model I)、壁面修正固相亚格子尺度过滤模型(Filtered Model II)和改进的固相亚格子尺度过滤模型(Filtered Model III)模拟NETL/PSRI挑战问题中的提升管内的颗粒流动特性,得到了时均气体压力梯度和时均轴向颗粒速度等分布。亚格子尺度模型和均匀流动模型(Huilin-Gidaspow model)的研究结果相比,改进的固相亚格子尺度过滤模型(Filtered Model III)与实验值更接近,尤其是对于高颗粒浓度流动。壁面修正可以提高压力梯度,从时均轴向颗粒速度分布曲线,可以看出在提升管内颗粒流动结构呈现更为明显的环核流动结构;同时,研究了提升管内气体压缩性、壁面修正和计算网格对模拟结果的影响,分析表明气体的可压缩性对提升管内轴向气体压力梯度有影响,在模拟计算时考虑气体的压缩性,可以提高计算精度。
