A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape fac...A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape factors of the ＂slot＂ and the preset depth used in ＂wetting-drying＂ algorithm. Two typical tests are conducted to examine the performance of the method with the effect of the shape factors of the ＂slot＂ being checked in detail in the first test. Numerical results demonstrate that： 1 ） no additional effort to improve the finite difference scheme is needed to implement ＂slot method＂ in DIVAST, and 2） ＂slot method＂ will simulate wetting and diying processes correctly if the shape factors of the ＂slot＂ being selected properly.展开更多
Using the slot method, the moving boundary problem caused by the change of the tide water elevation is treated. A two-dimensional advection - diffusion model with moving boundary is proposed, and the input pollutant i...Using the slot method, the moving boundary problem caused by the change of the tide water elevation is treated. A two-dimensional advection - diffusion model with moving boundary is proposed, and the input pollutant is considered as moving source to meet the water level variation. The model given in this paper has been used to simulate the pollutant transport in the Bohai Gulf, the computational results are in good agreement with the measured data.展开更多
Residual stress plays a vital role in the structural strength and stability. The determination of residual stress at single-point has become mature at present. However, the method to determine residual stress distribu...Residual stress plays a vital role in the structural strength and stability. The determination of residual stress at single-point has become mature at present. However, the method to determine residual stress distribution is still in shortage. For this problem, a finite element approach combined with slot milling method was developed in this study. In the method, firstly a slot is milled on the specimen surface to release the residual stress and then the released displacement field is measured by optical method, such as digital image correlation （DIC）, finally the finite element approach is used to determine the residual stress distribution along the slot. In order to verify the feasibility of the method, it was applied to study the residual stress introduced by shot peening, mainly about the stress distribution along the direction vertical to the shot peened surface. Since the influence depth of shot peening was too small, we utilized focused ion beam （FIB） to determine the microscale residual stress distribution. The result measured by X-ray diffraction （XRD） demonstrated that the method was feasible to determine the residual stress distribution.展开更多
基金the National Natural Science Foundation of China (Grant No.10702050)the Natural Science Foundation of Tianjin (Grant No.07JCYBJC07500)the Support Plan of Science and Technology of Tianjin (Grant No.07ZCGYSH01700)
文摘A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape factors of the ＂slot＂ and the preset depth used in ＂wetting-drying＂ algorithm. Two typical tests are conducted to examine the performance of the method with the effect of the shape factors of the ＂slot＂ being checked in detail in the first test. Numerical results demonstrate that： 1 ） no additional effort to improve the finite difference scheme is needed to implement ＂slot method＂ in DIVAST, and 2） ＂slot method＂ will simulate wetting and diying processes correctly if the shape factors of the ＂slot＂ being selected properly.
文摘Using the slot method, the moving boundary problem caused by the change of the tide water elevation is treated. A two-dimensional advection - diffusion model with moving boundary is proposed, and the input pollutant is considered as moving source to meet the water level variation. The model given in this paper has been used to simulate the pollutant transport in the Bohai Gulf, the computational results are in good agreement with the measured data.
基金supported by the National Natural Science Foundation of China(Grant Nos.11672153,11232008 & 11227801)
文摘Residual stress plays a vital role in the structural strength and stability. The determination of residual stress at single-point has become mature at present. However, the method to determine residual stress distribution is still in shortage. For this problem, a finite element approach combined with slot milling method was developed in this study. In the method, firstly a slot is milled on the specimen surface to release the residual stress and then the released displacement field is measured by optical method, such as digital image correlation （DIC）, finally the finite element approach is used to determine the residual stress distribution along the slot. In order to verify the feasibility of the method, it was applied to study the residual stress introduced by shot peening, mainly about the stress distribution along the direction vertical to the shot peened surface. Since the influence depth of shot peening was too small, we utilized focused ion beam （FIB） to determine the microscale residual stress distribution. The result measured by X-ray diffraction （XRD） demonstrated that the method was feasible to determine the residual stress distribution.
