The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
W Y Crutchfield - One of the best experts on this subject based on the ideXlab platform.
-
the thermal explosion revisited
arXiv: Numerical Analysis, 1999Co-Authors: Grigory Isaakovich Barenblatt, J. B. Bell, W Y CrutchfieldAbstract:The classical problem of the thermal explosion in a long cylindrical vessel is modified so that only a fraction $\a$ of its wall is ideally thermally conducting while the remaining fraction $1-\a$ is thermally isolated. Partial isolation of the wall naturally reduces the critical radius of the vessel. Most interesting is the case when the structure of the boundary is a periodic one, so that the alternating conductive $\a$ and isolated $1-\a$ parts of the boundary occupy together the segments $2\pi/N$ ($N$ is the number of segments) of the boundary. A numerical investigation is performed. It is shown that at small $\a$ and large $N$ the critical radius obeys a scaling law with the coefficients depending upon $N$. For large $N$ is obtained that in the central core of the vessel the temperature distribution is axisymmetric. In the boundary layer near the wall having the thickness $\approx 2\pi r_0/N$ ($r_0$--the radius of the vessel) the temperature distribution varies sharply in the Peripheral Direction. The temperature distribution in the axisymmetric core at the critical value of the vessel radius is subcritical
-
the thermal explosion revisited
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Grigory Isaakovich Barenblatt, J. B. Bell, W Y CrutchfieldAbstract:The classical problem of the thermal explosion in a long cylindrical vessel is modified so that only a fraction α of its wall is ideally thermally conducting while the remaining fraction 1−α is thermally isolated. Partial isolation of the wall naturally reduces the critical radius of the vessel. Most interesting is the case when the structure of the boundary is a periodic one, so that the alternating conductive α and isolated 1−α parts of the boundary occupy together the segments 2π/N (N is the number of segments) of the boundary. A numerical investigation is performed. It is shown that at small α and large N, the critical radius obeys a scaling law with the coefficients depending on N. For large N, the result is obtained that in the central core of the vessel the temperature distribution is axisymmetric. In the boundary layer near the wall having the thickness ≈2πr0/N (r0 is the radius of the vessel), the temperature distribution varies sharply in the Peripheral Direction. The temperature distribution in the axisymmetric core at the critical value of the vessel radius is subcritical.
Grigory Isaakovich Barenblatt - One of the best experts on this subject based on the ideXlab platform.
-
the thermal explosion revisited
arXiv: Numerical Analysis, 1999Co-Authors: Grigory Isaakovich Barenblatt, J. B. Bell, W Y CrutchfieldAbstract:The classical problem of the thermal explosion in a long cylindrical vessel is modified so that only a fraction $\a$ of its wall is ideally thermally conducting while the remaining fraction $1-\a$ is thermally isolated. Partial isolation of the wall naturally reduces the critical radius of the vessel. Most interesting is the case when the structure of the boundary is a periodic one, so that the alternating conductive $\a$ and isolated $1-\a$ parts of the boundary occupy together the segments $2\pi/N$ ($N$ is the number of segments) of the boundary. A numerical investigation is performed. It is shown that at small $\a$ and large $N$ the critical radius obeys a scaling law with the coefficients depending upon $N$. For large $N$ is obtained that in the central core of the vessel the temperature distribution is axisymmetric. In the boundary layer near the wall having the thickness $\approx 2\pi r_0/N$ ($r_0$--the radius of the vessel) the temperature distribution varies sharply in the Peripheral Direction. The temperature distribution in the axisymmetric core at the critical value of the vessel radius is subcritical
-
the thermal explosion revisited
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Grigory Isaakovich Barenblatt, J. B. Bell, W Y CrutchfieldAbstract:The classical problem of the thermal explosion in a long cylindrical vessel is modified so that only a fraction α of its wall is ideally thermally conducting while the remaining fraction 1−α is thermally isolated. Partial isolation of the wall naturally reduces the critical radius of the vessel. Most interesting is the case when the structure of the boundary is a periodic one, so that the alternating conductive α and isolated 1−α parts of the boundary occupy together the segments 2π/N (N is the number of segments) of the boundary. A numerical investigation is performed. It is shown that at small α and large N, the critical radius obeys a scaling law with the coefficients depending on N. For large N, the result is obtained that in the central core of the vessel the temperature distribution is axisymmetric. In the boundary layer near the wall having the thickness ≈2πr0/N (r0 is the radius of the vessel), the temperature distribution varies sharply in the Peripheral Direction. The temperature distribution in the axisymmetric core at the critical value of the vessel radius is subcritical.
J. B. Bell - One of the best experts on this subject based on the ideXlab platform.
-
the thermal explosion revisited
arXiv: Numerical Analysis, 1999Co-Authors: Grigory Isaakovich Barenblatt, J. B. Bell, W Y CrutchfieldAbstract:The classical problem of the thermal explosion in a long cylindrical vessel is modified so that only a fraction $\a$ of its wall is ideally thermally conducting while the remaining fraction $1-\a$ is thermally isolated. Partial isolation of the wall naturally reduces the critical radius of the vessel. Most interesting is the case when the structure of the boundary is a periodic one, so that the alternating conductive $\a$ and isolated $1-\a$ parts of the boundary occupy together the segments $2\pi/N$ ($N$ is the number of segments) of the boundary. A numerical investigation is performed. It is shown that at small $\a$ and large $N$ the critical radius obeys a scaling law with the coefficients depending upon $N$. For large $N$ is obtained that in the central core of the vessel the temperature distribution is axisymmetric. In the boundary layer near the wall having the thickness $\approx 2\pi r_0/N$ ($r_0$--the radius of the vessel) the temperature distribution varies sharply in the Peripheral Direction. The temperature distribution in the axisymmetric core at the critical value of the vessel radius is subcritical
-
the thermal explosion revisited
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Grigory Isaakovich Barenblatt, J. B. Bell, W Y CrutchfieldAbstract:The classical problem of the thermal explosion in a long cylindrical vessel is modified so that only a fraction α of its wall is ideally thermally conducting while the remaining fraction 1−α is thermally isolated. Partial isolation of the wall naturally reduces the critical radius of the vessel. Most interesting is the case when the structure of the boundary is a periodic one, so that the alternating conductive α and isolated 1−α parts of the boundary occupy together the segments 2π/N (N is the number of segments) of the boundary. A numerical investigation is performed. It is shown that at small α and large N, the critical radius obeys a scaling law with the coefficients depending on N. For large N, the result is obtained that in the central core of the vessel the temperature distribution is axisymmetric. In the boundary layer near the wall having the thickness ≈2πr0/N (r0 is the radius of the vessel), the temperature distribution varies sharply in the Peripheral Direction. The temperature distribution in the axisymmetric core at the critical value of the vessel radius is subcritical.
Dingwen Yu - One of the best experts on this subject based on the ideXlab platform.
-
prediction of surface residual stress after end milling based on cutting force and temperature
Journal of Materials Processing Technology, 2016Co-Authors: Pingfa Feng, Jianfu Zhang, Zhijun Wu, Dingwen YuAbstract:Abstract Residual stress in the machined surface can significantly influence the performance of machined parts. In recent years many researches have been carried out to measure and predict the machining-induced residual stress, where the machining-induced residual stress is often regarded as the function of machining parameters. Yet it is the combined effect of the thermal and mechanical loads that directly affect the stress field during cutting process. In this research, the cutting forces and cutting temperature were measured during end milling process with different feed rate and depth of cut, and the surface residual stress along Peripheral Direction was measured after machining. The effect of thermal and mechanical loads on the formation process of residual stress was analyzed, and a new prediction model was proposed, which specifies the effect of thermal and mechanical loads, and which also takes into consideration the influence of feed rate and the depth of cut. Generally the thermal loads drive the surface stress to be more tensile, while the mechanical loads have the opposite effect. Larger feed rate weakens the effect of cutting forces on unit area of machined surface remarkably, while the influence of the depth of but is less significant. Under the cutting conditions in this research, the surface residual stress along Peripheral Direction is tensile, which indicates that the thermal effect plays the dominant role in forming residual stress. The coefficients in the proposed model were determined with experimental data, and the model was preliminarily verified. It might be a useful method to achieve a real-time prediction and control of machining-induced residual stress by monitoring cutting forces and temperature.
Xinzheng Wang - One of the best experts on this subject based on the ideXlab platform.
-
a biomimetic engineered grinding wheel inspired by phyllotaxis theory
Journal of Materials Processing Technology, 2018Co-Authors: Haiyue Yu, Jun Wang, Xinzheng WangAbstract:Abstract In comparison with the conventional grinding wheels (GWs), GWs with defined grain distributions (or engineered GWs) have been widely explored and studied due to the stable grain-workpiece interactions. However, in most previous studies, grains were allocated at linearly-distributed positions without any theoretical models or foundations. To fill this gap, the GW with a phyllotactic grain distribution inspired by the phyllotaxis theory in biology is proposed in this paper. By analyzing the evenness of phyllotactic pattern in the Peripheral Direction and expanded view, the grain distribution parameters are theoretically designed and manufactured firstly. Then, the condition of grinding fluid in the grinding zone was observed and analyzed to verify the superiority of the grinding wheel with abrasive phyllotactic pattern by using the method of finite element modeling (FEM) contrastively. Finally, to evaluate the proposed practicality of the biomimetic engineered grinding wheel, some comparative grinding experiments of grinding surface roughness and wear were conducted. In conclusion, the advantages of biomimetic engineered grinding wheel inspired by phyllotaxis theory were demonstrated and approved.