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Yixue Chen - One of the best experts on this subject based on the ideXlab platform.

  • a finite size pencil beam for imrt dose optimization a simpler Analytical Function for the finite size pencil beam kernel
    Physics in Medicine and Biology, 2006
    Co-Authors: Yican Wu, Yixue Chen
    Abstract:

    A simple and finite-termed Analytical Function for the finite size pencil beam kernel was constructed. The dose cross-profile of a semi-infinite field with field edge at x = 0 can be well fitted by the Boltzmann Function. The pencil beam cross-profile of width 2x0 can be obtained as the difference between two semi-infinite fields shifted by 2x0. If the profile is centred about x = 0, it can derive from P(x + x0) − P(x − x0). The penumbra influence can be taken by the penumbra tuning factor f. The parameters A1, A2, A3, A4, f can be obtained by fitting depth–dose curves and cross-profiles for a set of square fields. The two-dimensional dose distribution F(x, y, x0, y0, A1, A2, A3, A4, f1, f2) of a pencil beam of width (2x0, 2y0) is defined by multiplication of two independent one-dimensional profiles.

D B Ingham - One of the best experts on this subject based on the ideXlab platform.

  • a boundary integral technique for the numerical modelling of the air flow for the aaberg exhaust system
    Engineering Analysis With Boundary Elements, 2000
    Co-Authors: X Wen, G R Hunt, D B Ingham
    Abstract:

    Abstract A boundary integral technique has been developed for the numerical simulation of the air flow for the Aaberg exhaust system. For the steady, ideal, irrotational air flow induced by a jet, the air velocity is an Analytical Function. The solution of the problem is formulated in the form of a boundary integral equation by seeking the solution of a mixed boundary-value problem of an Analytical Function based on the Riemann–Hilbert technique. The boundary integral equation is numerically solved by converting it into a system of linear algebraic equations, which are solved by the process of the Gaussian elimination. The air velocity vector at any point in the solution domain is then computed from the air velocity on the boundary of the solution domain.

  • the generation of an orthogonal grid by the use of a boundary integral technique
    Engineering Analysis With Boundary Elements, 1998
    Co-Authors: X Wen, D B Ingham, N Dombrowski, E A Foumeny
    Abstract:

    Abstract A new boundary integral technique is developed for the two-dimensional, irrotational, incompressible fluid flow in complex geometries and the method is applied to the generation of an orthogonal grid system which can be used for solving laminar and turbulent fluid flows in the same geometries. The integral equation for the potential flow is derived from the Dirichlet boundary problem for an Analytical Function on the upper half plane, and then the integral-differential equations are obtained on the boundary of the solution domain in the physical plane. An iterative procedure is developed to solve the integral-differential equations in order to obtain the potential flow solution. To illustrate the grid generation technique several classical two-dimensional CFD problems have been investigated and the method has been extended to generate a less distorted grid system for a three-dimensional fluid flow.

X Wen - One of the best experts on this subject based on the ideXlab platform.

  • a boundary integral technique for the numerical modelling of the air flow for the aaberg exhaust system
    Engineering Analysis With Boundary Elements, 2000
    Co-Authors: X Wen, G R Hunt, D B Ingham
    Abstract:

    Abstract A boundary integral technique has been developed for the numerical simulation of the air flow for the Aaberg exhaust system. For the steady, ideal, irrotational air flow induced by a jet, the air velocity is an Analytical Function. The solution of the problem is formulated in the form of a boundary integral equation by seeking the solution of a mixed boundary-value problem of an Analytical Function based on the Riemann–Hilbert technique. The boundary integral equation is numerically solved by converting it into a system of linear algebraic equations, which are solved by the process of the Gaussian elimination. The air velocity vector at any point in the solution domain is then computed from the air velocity on the boundary of the solution domain.

  • the generation of an orthogonal grid by the use of a boundary integral technique
    Engineering Analysis With Boundary Elements, 1998
    Co-Authors: X Wen, D B Ingham, N Dombrowski, E A Foumeny
    Abstract:

    Abstract A new boundary integral technique is developed for the two-dimensional, irrotational, incompressible fluid flow in complex geometries and the method is applied to the generation of an orthogonal grid system which can be used for solving laminar and turbulent fluid flows in the same geometries. The integral equation for the potential flow is derived from the Dirichlet boundary problem for an Analytical Function on the upper half plane, and then the integral-differential equations are obtained on the boundary of the solution domain in the physical plane. An iterative procedure is developed to solve the integral-differential equations in order to obtain the potential flow solution. To illustrate the grid generation technique several classical two-dimensional CFD problems have been investigated and the method has been extended to generate a less distorted grid system for a three-dimensional fluid flow.

Yican Wu - One of the best experts on this subject based on the ideXlab platform.

  • a finite size pencil beam for imrt dose optimization a simpler Analytical Function for the finite size pencil beam kernel
    Physics in Medicine and Biology, 2006
    Co-Authors: Yican Wu, Yixue Chen
    Abstract:

    A simple and finite-termed Analytical Function for the finite size pencil beam kernel was constructed. The dose cross-profile of a semi-infinite field with field edge at x = 0 can be well fitted by the Boltzmann Function. The pencil beam cross-profile of width 2x0 can be obtained as the difference between two semi-infinite fields shifted by 2x0. If the profile is centred about x = 0, it can derive from P(x + x0) − P(x − x0). The penumbra influence can be taken by the penumbra tuning factor f. The parameters A1, A2, A3, A4, f can be obtained by fitting depth–dose curves and cross-profiles for a set of square fields. The two-dimensional dose distribution F(x, y, x0, y0, A1, A2, A3, A4, f1, f2) of a pencil beam of width (2x0, 2y0) is defined by multiplication of two independent one-dimensional profiles.

L. Lapuyade - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of SiC ceramics with complex porosity by capillary infiltration: Part B – Filling by molten silicon at 1500 °C
    Journal of the European Ceramic Society, 2020
    Co-Authors: Jérôme Roger, M. Avenel, L. Lapuyade
    Abstract:

    In Part A of this study, infiltrations experiments of porous SiC samples by hexadecane with pore-size distributions comprising small and large pores were realized. Two successive stages were identified during the filling of these samples corresponding to the infiltration of the two types of pores. The experimental data were successfully treated with a new Analytical Function. In Part B, it was found that this Function can also be applied to the analysis of the mass gain during molten silicon infiltration at 1500°C. Prior to silicon infiltration, it was found that the operating temperature induces a shift of the pore size distributions towards larger values. A dissolution-recrystallisation mechanism can also occur during the infiltration of silicon. During the first stage, liquid silicon fills rapidly larger pores than hexadecane. The kinetics are significantly larger with liquid silicon. Consequently, the durations for the complete filling are very short with molten silicon.