By the aid of an idea of the weighted ENO schemes, some weight-type high-resolution difference schemes with different orders of accuracy are presented in this paper by using suitable weights instead of the minmod func...By the aid of an idea of the weighted ENO schemes, some weight-type high-resolution difference schemes with different orders of accuracy are presented in this paper by using suitable weights instead of the minmod functions appearing in various TVD schemes. Numerical comparisons between the weighted schemes and the non-weighted schemes have been done for scalar equation, one-dimensional Euler equations, two-dimensional Navier-Stokes equations and parabolized Navier-Stokes equations.展开更多
The numerical method which is based on flux difference splitting, LUdecomposition, and implicit high-resolution third-order Essentially Non-Oscillatory (ENO) scheme wasconstructed for the efficient computation of stea...The numerical method which is based on flux difference splitting, LUdecomposition, and implicit high-resolution third-order Essentially Non-Oscillatory (ENO) scheme wasconstructed for the efficient computation of steady state solution to three-dimensionalincompressible Navier-Stokes e-quations in general coordinates. The flowfields over underwateraxisymmetric bodies, full-appended axisymmetric bodies and axisymetric bodies with a ring-wing ductwere simulated. The method is proved to be capable of predicting the circumferential-mean velocitydistribution at model scale to the accuracy of around 3% of measured values, and of predicting somedetails of flow features, for example, the wake harmonics.展开更多
This is the continuation of the paper”Central discontinuous Galerkin methods on overlapping cells with a non-oscillatory hierarchical reconstruction”by the same authors.The hierarchical reconstruction introduced the...This is the continuation of the paper”Central discontinuous Galerkin methods on overlapping cells with a non-oscillatory hierarchical reconstruction”by the same authors.The hierarchical reconstruction introduced therein is applied to central schemes on overlapping cells and to finite volume schemes on non-staggered grids.This takes a new finite volume approach for approximating non-smooth solutions.A critical step for high-order finite volume schemes is to reconstruct a non-oscillatory high degree polynomial approximation in each cell out of nearby cell averages.In the paper this procedure is accomplished in two steps:first to reconstruct a high degree polynomial in each cell by using e.g.,a central reconstruction,which is easy to do despite the fact that the reconstructed polynomial could be oscillatory;then to apply the hierarchical reconstruction to remove the spurious oscillations while maintaining the high resolution.All numerical computations for systems of conservation laws are performed without characteristic decomposition.In particular,we demonstrate that this new approach can generate essentially non-oscillatory solutions even for 5th-order schemes without characteristic decomposition.展开更多
OBJECTIVE: To observe the effects of Suhuang Zhike Capsules on lung function and peripheral blood eosinophil count (EOS) and exhaled nitric oxide (eNO) in patients with acute asthma attack.METHODS: A total of 80 patie...OBJECTIVE: To observe the effects of Suhuang Zhike Capsules on lung function and peripheral blood eosinophil count (EOS) and exhaled nitric oxide (eNO) in patients with acute asthma attack.METHODS: A total of 80 patients with acute exacerbation of bronchial asthma admitted to Huai'an Cancer Hospital from January 2017 to January 2018 were randomly divided into an observation group and a control group,with 40 cases in each group.The control group was given conventional treatment with western medicine,and the observation group was given Suhuang Zhike Capsules on the basis of the treatment method of the control group.After 1 week of treatment,the improvement of individual symptoms (cough,wheezing,wheezing rale),lung function [1 second forced expiratory volume (FEV1),forced expiratory volume occupational capacity of vital capacity (FVC) in 1 second and peak expiratory flow (PEF)] and peripheral blood EOS and eNO levels and efficacy before and after the treatment were observed and assessed.RESULTS: The total effective rate of the observation group was 92.5%,which was significantly higher than the total effective rate of the control group (75.0%)(P < 0.05).The cough,wheezing and wheezing scores of the 2 groups were significantly decreased after treatment (P < 0.05).The scores of the above symptoms were significantly lower in the observation group than in the control group (P < 0.05).The FEV1,FVC and PEF were significantly increased after treatment (P < 0.05),and the above lung functions in the observation group were significantly higher than the control group (all P < 0.05).The EOS and eNO levels in the peripheral blood of the 2 groups were significantly decreased after treatment (P < 0.05),and the EOS and eNO levels in the peripheral blood in the observation group were significantly lower than those in the control group (P < 0.05).CONCLUSION: Suhuang Zhike Capsules can reduce the levels of EOS and eNO in peripheral blood of patients with acute asthma attack,improve the lung function of patients,relieve the clinical sym展开更多
Computational gas dynamical simulations using the WENO-LF method are applied to modeling the high Mach number astrophysical jet XZ Tauri, including the effects of radiative cooling. Mach 55 simulations of the pulsed p...Computational gas dynamical simulations using the WENO-LF method are applied to modeling the high Mach number astrophysical jet XZ Tauri, including the effects of radiative cooling. Mach 55 simulations of the pulsed proto-jet are presented and analyzed in terms of interacting nonlinear waves： terminal Mach disks, bow shocks, and Meshkov-Richtmyer instabilities of the leading jet contact boundary.展开更多
Three dimensional steady flowfield generated by transverse sonic injection Into a supersonic flow was simulated by solving the Favre-averaged Navier-Stokes equations using the weighted essentially nonoscillatory (WENO...Three dimensional steady flowfield generated by transverse sonic injection Into a supersonic flow was simulated by solving the Favre-averaged Navier-Stokes equations using the weighted essentially nonoscillatory (WENO) schemes and Jones-Launder k-epsilon model. Results indicate that in the upstream of the square injection there exist two main recirculation regions and the primary vortex induces the horseshoe vortex region. In the downstream there is a low pressure region which conduces a pair of helical vortex.展开更多
基金The project supported by the National Natural Science Foundation of China (19582007) Partly by State Key Laboratory of Scientific/Engineering Computing
文摘By the aid of an idea of the weighted ENO schemes, some weight-type high-resolution difference schemes with different orders of accuracy are presented in this paper by using suitable weights instead of the minmod functions appearing in various TVD schemes. Numerical comparisons between the weighted schemes and the non-weighted schemes have been done for scalar equation, one-dimensional Euler equations, two-dimensional Navier-Stokes equations and parabolized Navier-Stokes equations.
文摘The numerical method which is based on flux difference splitting, LUdecomposition, and implicit high-resolution third-order Essentially Non-Oscillatory (ENO) scheme wasconstructed for the efficient computation of steady state solution to three-dimensionalincompressible Navier-Stokes e-quations in general coordinates. The flowfields over underwateraxisymmetric bodies, full-appended axisymmetric bodies and axisymetric bodies with a ring-wing ductwere simulated. The method is proved to be capable of predicting the circumferential-mean velocitydistribution at model scale to the accuracy of around 3% of measured values, and of predicting somedetails of flow features, for example, the wake harmonics.
基金supported in part by NSF grant DMS-0511815.The research of C.-W.Shu was supported in part by the Chinese Academy of Sciences while this author was visiting the University of Science and Technology of China(grant 2004-1-8)+3 种基金the Institute of Computational Mathematics and Scientific/Engineering ComputingAdditional support was provided by ARO grant W911NF-04-1-0291 and NSF grant DMS0510345The research of E.Tadmor was supported in part by NSF grant 04-07704 and ONR grant N00014-91-J-1076The research of M.Zhang was supported in part by the Chinese Academy of Sciences grant 2004-1-8.
文摘This is the continuation of the paper”Central discontinuous Galerkin methods on overlapping cells with a non-oscillatory hierarchical reconstruction”by the same authors.The hierarchical reconstruction introduced therein is applied to central schemes on overlapping cells and to finite volume schemes on non-staggered grids.This takes a new finite volume approach for approximating non-smooth solutions.A critical step for high-order finite volume schemes is to reconstruct a non-oscillatory high degree polynomial approximation in each cell out of nearby cell averages.In the paper this procedure is accomplished in two steps:first to reconstruct a high degree polynomial in each cell by using e.g.,a central reconstruction,which is easy to do despite the fact that the reconstructed polynomial could be oscillatory;then to apply the hierarchical reconstruction to remove the spurious oscillations while maintaining the high resolution.All numerical computations for systems of conservation laws are performed without characteristic decomposition.In particular,we demonstrate that this new approach can generate essentially non-oscillatory solutions even for 5th-order schemes without characteristic decomposition.
文摘OBJECTIVE: To observe the effects of Suhuang Zhike Capsules on lung function and peripheral blood eosinophil count (EOS) and exhaled nitric oxide (eNO) in patients with acute asthma attack.METHODS: A total of 80 patients with acute exacerbation of bronchial asthma admitted to Huai'an Cancer Hospital from January 2017 to January 2018 were randomly divided into an observation group and a control group,with 40 cases in each group.The control group was given conventional treatment with western medicine,and the observation group was given Suhuang Zhike Capsules on the basis of the treatment method of the control group.After 1 week of treatment,the improvement of individual symptoms (cough,wheezing,wheezing rale),lung function [1 second forced expiratory volume (FEV1),forced expiratory volume occupational capacity of vital capacity (FVC) in 1 second and peak expiratory flow (PEF)] and peripheral blood EOS and eNO levels and efficacy before and after the treatment were observed and assessed.RESULTS: The total effective rate of the observation group was 92.5%,which was significantly higher than the total effective rate of the control group (75.0%)(P < 0.05).The cough,wheezing and wheezing scores of the 2 groups were significantly decreased after treatment (P < 0.05).The scores of the above symptoms were significantly lower in the observation group than in the control group (P < 0.05).The FEV1,FVC and PEF were significantly increased after treatment (P < 0.05),and the above lung functions in the observation group were significantly higher than the control group (all P < 0.05).The EOS and eNO levels in the peripheral blood of the 2 groups were significantly decreased after treatment (P < 0.05),and the EOS and eNO levels in the peripheral blood in the observation group were significantly lower than those in the control group (P < 0.05).CONCLUSION: Suhuang Zhike Capsules can reduce the levels of EOS and eNO in peripheral blood of patients with acute asthma attack,improve the lung function of patients,relieve the clinical sym
文摘Computational gas dynamical simulations using the WENO-LF method are applied to modeling the high Mach number astrophysical jet XZ Tauri, including the effects of radiative cooling. Mach 55 simulations of the pulsed proto-jet are presented and analyzed in terms of interacting nonlinear waves： terminal Mach disks, bow shocks, and Meshkov-Richtmyer instabilities of the leading jet contact boundary.
文摘Three dimensional steady flowfield generated by transverse sonic injection Into a supersonic flow was simulated by solving the Favre-averaged Navier-Stokes equations using the weighted essentially nonoscillatory (WENO) schemes and Jones-Launder k-epsilon model. Results indicate that in the upstream of the square injection there exist two main recirculation regions and the primary vortex induces the horseshoe vortex region. In the downstream there is a low pressure region which conduces a pair of helical vortex.
