Data reconciliation technology can decrease the level of corruption of process data due to measurement noise, but the presence of outliers caused by process peaks or unmeasured disturbances will smear the reconciled r...Data reconciliation technology can decrease the level of corruption of process data due to measurement noise, but the presence of outliers caused by process peaks or unmeasured disturbances will smear the reconciled results. Based on the analysis of limitation of conventional outlier detection algorithms, a modified outlier detection method in dynamic data reconciliation (DDR) is proposed in this paper. In the modified method, the outliers of each variable are distinguished individually and the weight is modified accordingly. Therefore, the modified method can use more information of normal data, and can efficiently decrease the effect of outliers. Simulation of a continuous stirred tank reactor (CSTR) process verifies the effectiveness of the proposed algorithm.展开更多
We present in this paper several efficient numerical schemes for the magneto-hydrodynamic(MHD)equations. These semi-discretized(in time) schemes are based on the standard and rotational pressure-correction schemes for...We present in this paper several efficient numerical schemes for the magneto-hydrodynamic(MHD)equations. These semi-discretized(in time) schemes are based on the standard and rotational pressure-correction schemes for the Navier-Stokes equations and do not involve a projection step for the magnetic field. We show that these schemes are unconditionally energy stable, present an effective algorithm for their fully discrete versions and carry out demonstrative numerical experiments.展开更多
A particle mapping transportation algorithm was proposed on the basis of the particle-in-cell method.The particles with rectangular influence domains were employed in the transportation algorithm to reduce the numeric...A particle mapping transportation algorithm was proposed on the basis of the particle-in-cell method.The particles with rectangular influence domains were employed in the transportation algorithm to reduce the numerical fluctuations.Based on the error analysis in the process of particle motion computation,a prediction-correction algorithm was introduced to improve the computational accuracy.Furthermore,the performance of the particle mapping transportation method was evaluated by using the rotation,the slotted disk and the shear advection tests,and the results were compared with other interface reconstruction methods.Finally,the hemispherical projectile penetration into a steel target was numerically simulated.The results showed that the proposed method produced less numerical fluctuations and exhibited clear material interfaces,which indicated that it is accurate and effective.展开更多
An efficient iterative algorithm is presented for the numerical solution of viscous incompressible Navier-Stokes equations based on Taylor-Galerkin like split and pressure correction method in this paper. Taylor-Hood ...An efficient iterative algorithm is presented for the numerical solution of viscous incompressible Navier-Stokes equations based on Taylor-Galerkin like split and pressure correction method in this paper. Taylor-Hood element is introduced to overcome the numerical difficulties arising from the fluid incompressibility. In order to confirm the properties of the algorithm, the numerical simulation on plane Poisseuille flow problem and lid- driven cavity flow problem with different Reynolds numbers is presented. The numerical results indicate that the proposed iterative version can be effectively applied to the simulation of viscous incompressible flows. Moreover, the proposed iterative version has a better overall performance in maximum time step size allowed, under comparable convergence rate, stability and accuracy, than other tested versions in numerical solutions of the plane PoisseuiUe flow with different Reynolds numbers ranging from low to high viscosities.展开更多
In this paper,a multiscale problem arising in material science is considered.The problem involves a random coefficient which is assumed to be a perturbation of a deterministic coefficient,in a sense made precisely in ...In this paper,a multiscale problem arising in material science is considered.The problem involves a random coefficient which is assumed to be a perturbation of a deterministic coefficient,in a sense made precisely in the body of the text.The homogenized limit is then computed by using a perturbation approach.This computation requires repeatedly solving a corrector-like equation for various configurations of the material.For this purpose,the reduced basis approach is employed and adapted to the specific context.The authors perform numerical tests that demonstrate the efficiency of the approach.展开更多
基金Supported by the National Outstanding Youth Science Foundation of China (No. 60025308) and Key Technologies R&DProgram in the 10th Five-year Plan (No. 2001BA204B07)
文摘Data reconciliation technology can decrease the level of corruption of process data due to measurement noise, but the presence of outliers caused by process peaks or unmeasured disturbances will smear the reconciled results. Based on the analysis of limitation of conventional outlier detection algorithms, a modified outlier detection method in dynamic data reconciliation (DDR) is proposed in this paper. In the modified method, the outliers of each variable are distinguished individually and the weight is modified accordingly. Therefore, the modified method can use more information of normal data, and can efficiently decrease the effect of outliers. Simulation of a continuous stirred tank reactor (CSTR) process verifies the effectiveness of the proposed algorithm.
基金supported by National Science Foundation of USA (Grant No. DMS1419053)
文摘We present in this paper several efficient numerical schemes for the magneto-hydrodynamic(MHD)equations. These semi-discretized(in time) schemes are based on the standard and rotational pressure-correction schemes for the Navier-Stokes equations and do not involve a projection step for the magnetic field. We show that these schemes are unconditionally energy stable, present an effective algorithm for their fully discrete versions and carry out demonstrative numerical experiments.
基金supported by the National Basic Research Program of China(Grant No.2010CB832706)the National Natural Science Foundation of China(Grant Nos.11032002 and 11172041)the Project of State Key Laboratory of Explosion Science and Technology(Grant No. ZDKT10-03c)
文摘A particle mapping transportation algorithm was proposed on the basis of the particle-in-cell method.The particles with rectangular influence domains were employed in the transportation algorithm to reduce the numerical fluctuations.Based on the error analysis in the process of particle motion computation,a prediction-correction algorithm was introduced to improve the computational accuracy.Furthermore,the performance of the particle mapping transportation method was evaluated by using the rotation,the slotted disk and the shear advection tests,and the results were compared with other interface reconstruction methods.Finally,the hemispherical projectile penetration into a steel target was numerically simulated.The results showed that the proposed method produced less numerical fluctuations and exhibited clear material interfaces,which indicated that it is accurate and effective.
基金the National Natural Science Foundation of China (No. 50778111)the Key Project of Fund of Science and Technology Development of Shanghai(No. 07JC14023)the Doctoral Disciplinary Special Research Project of Chinese Ministry of Education(No. 200802480056)
文摘An efficient iterative algorithm is presented for the numerical solution of viscous incompressible Navier-Stokes equations based on Taylor-Galerkin like split and pressure correction method in this paper. Taylor-Hood element is introduced to overcome the numerical difficulties arising from the fluid incompressibility. In order to confirm the properties of the algorithm, the numerical simulation on plane Poisseuille flow problem and lid- driven cavity flow problem with different Reynolds numbers is presented. The numerical results indicate that the proposed iterative version can be effectively applied to the simulation of viscous incompressible flows. Moreover, the proposed iterative version has a better overall performance in maximum time step size allowed, under comparable convergence rate, stability and accuracy, than other tested versions in numerical solutions of the plane PoisseuiUe flow with different Reynolds numbers ranging from low to high viscosities.
基金Project supported by EOARD(European Office of Aerospace Research and Development) (No.FA865510-C-4002)
文摘In this paper,a multiscale problem arising in material science is considered.The problem involves a random coefficient which is assumed to be a perturbation of a deterministic coefficient,in a sense made precisely in the body of the text.The homogenized limit is then computed by using a perturbation approach.This computation requires repeatedly solving a corrector-like equation for various configurations of the material.For this purpose,the reduced basis approach is employed and adapted to the specific context.The authors perform numerical tests that demonstrate the efficiency of the approach.
