The Experts below are selected from a list of 3429 Experts worldwide ranked by ideXlab platform

Shin Yoshizawa - One of the best experts on this subject based on the ideXlab platform.

  • on Evolute cusps and skeleton bifurcations
    International Conference on Shape Modeling and Applications, 2001
    Co-Authors: Alexander Belyaev, Shin Yoshizawa
    Abstract:

    Consider a 2D smooth closed curve evolving in time, the skeleton (medial axis) of the figure bounded by the curve, and the Evolute of the curve. A new branch of the skeleton can appear/disappear when an Evolute cusp intersects the skeleton. In this paper, we describe exact conditions of the skeleton bifurcations corresponding to such intersections. Similar results are also obtained for 3D surfaces evolving in time.

  • Shape Modeling International - On Evolute cusps and skeleton bifurcations
    Proceedings International Conference on Shape Modeling and Applications, 1
    Co-Authors: Alexander Belyaev, Shin Yoshizawa
    Abstract:

    Consider a 2D smooth closed curve evolving in time, the skeleton (medial axis) of the figure bounded by the curve, and the Evolute of the curve. A new branch of the skeleton can appear/disappear when an Evolute cusp intersects the skeleton. In this paper, we describe exact conditions of the skeleton bifurcations corresponding to such intersections. Similar results are also obtained for 3D surfaces evolving in time.

Alexander Belyaev - One of the best experts on this subject based on the ideXlab platform.

  • on Evolute cusps and skeleton bifurcations
    International Conference on Shape Modeling and Applications, 2001
    Co-Authors: Alexander Belyaev, Shin Yoshizawa
    Abstract:

    Consider a 2D smooth closed curve evolving in time, the skeleton (medial axis) of the figure bounded by the curve, and the Evolute of the curve. A new branch of the skeleton can appear/disappear when an Evolute cusp intersects the skeleton. In this paper, we describe exact conditions of the skeleton bifurcations corresponding to such intersections. Similar results are also obtained for 3D surfaces evolving in time.

  • Shape Modeling International - On Evolute cusps and skeleton bifurcations
    Proceedings International Conference on Shape Modeling and Applications, 1
    Co-Authors: Alexander Belyaev, Shin Yoshizawa
    Abstract:

    Consider a 2D smooth closed curve evolving in time, the skeleton (medial axis) of the figure bounded by the curve, and the Evolute of the curve. A new branch of the skeleton can appear/disappear when an Evolute cusp intersects the skeleton. In this paper, we describe exact conditions of the skeleton bifurcations corresponding to such intersections. Similar results are also obtained for 3D surfaces evolving in time.

Salim Yüce - One of the best experts on this subject based on the ideXlab platform.

  • Special Involute-Evolute Partner D -Curves in E 3
    European Journal of Pure and Applied Mathematics, 2013
    Co-Authors: Salim Yüce
    Abstract:

    I n this paper, we take into account the opinion of involute-Evolute curves which lie on fully surfaces and by taking into account the Darboux frames of them we illustrate these curves as special involute-Evolute partner D-curves in E 3 . Besides, we find the relations between the normal curvatures, the geodesic curvatures and the geodesic torsions of these curves. Finally, some consequences and examples are given. 2010 Mathematics Subject Classifications: 53A04

  • Special involute-Evolute partner D-curves in E3
    arXiv: Differential Geometry, 2012
    Co-Authors: Özcan Bektaş, Salim Yüce
    Abstract:

    In this paper, we take into account the opinion of involute-Evolute curves which lie on fully surfaces and by taking into account the Darboux frames of them we illustrate these curves as special involute-Evolute partner D-curves in E3. Besides, we find the relations between the normal curvatures, the geodesic curvatures and the geodesic torsions of these curves. Finally, some consequences and examples are given.

A. Elsharkawy - One of the best experts on this subject based on the ideXlab platform.

Seiichi Ibaraki - One of the best experts on this subject based on the ideXlab platform.

  • An investigation of volute cross-sectional shape on turbocharger turbine under pulsating conditions in internal combustion engine
    Energy Conversion and Management, 2015
    Co-Authors: Mingyang Yang, Srithar Rajoo, Ricardo F. Martinez-botas, Takao Yokoyama, Seiichi Ibaraki
    Abstract:

    Engine downsizing is a proven method for CO2 reduction in Internal Combustion Engine (ICE). A turbocharger, which reclaims the energy from the exhaust gas to boost the intake air, can effectively improve the power density of the engine thus is one of the key enablers to achieve the engine downsizing. Acknowledging its importance, many research efforts have gone into improving a turbocharger performance, which includes turbine volute. The cross-section design of a turbine volute in a turbocharger is usually a compromise between the engine level packaging and desired performance. Thus, it is beneficial to evaluate the effects of cross-sectional shape on a turbine performance. This paper presents experimental and computational investigation of the influence of volute cross-sectional shape on the performance of a radial turbocharger turbine under pulsating conditions. The cross-sectional shape of the baseline volute (denoted as Volute B) was optimized (Volute A) while the annulus distribution of area-to-radius ratio (A/R) for the two volute configurations are kept the same. Experimental results show that the turbine with the optimized volute A has better cycle averaged efficiency under pulsating flow conditions, for different loadings and frequencies. The advantage of performance is influenced by the operational conditions. After the experiment, a validated unsteady computational fluid dynamics (CFD) modeling was employed to investigate the mechanism by which performance differs between the baseline volute and the optimized version. Computational results show a stronger flow distortion in spanwise direction at the rotor inlet with the baseline volute. Furthermore, compared with the optimized volute, the flow distortion is more sensitive to the pulsating flow conditions in the baseline volute. This is due to the different secondary flow pattern in the cross-sections, hence demonstrating a direction for desired volute cross-sectional shape to be used in a turbocharger radial turbine for internal combustion engine.

  • influence of volute cross sectional shape of a nozzleless turbocharger turbine under pulsating flow conditions
    ASME Turbo Expo 2014: Turbine Technical Conference and Exposition GT 2014, 2014
    Co-Authors: Mingyang Yang, Srithar Rajoo, Takao Yokoyama, Ricardo Martinezbotas, Seiichi Ibaraki
    Abstract:

    This paper presents an experimental and computational investigation of the influence of volute cross-sectional shape on the performance of a radial turbocharger turbine under pulsating conditions. Two volute configurations (denoted volute A and B) with the same area-to-radius ratio (A/R) distribution but different aspect ratios are rapid prototyped and tested with a same radial rotor. Experimental results show that the turbine with smaller aspect ratio volute (volute A), which has a squarish shape, shows consistently better cycle averaged efficiency at different loadings and frequencies, and the magnitude of improvement is influenced by the operational conditions. In consequent to experiments, a reduced order unsteady computational fluid dynamics (CFD) method was employed to investigate the mechanism of the performance discrepancies between volute A and B. Computational results show a stronger flow angle distortion in both circumferential and spanwise direction for volute B. Furthermore, compared with the volute A, the flow distortion near the shroud at the rotor inlet is evidently amplified by the volute B under pulsating conditions compared with the corresponding steady condition. Results in this paper, in general, demonstrate a direction for desired volute cross-sectional shape to be used in a turbocharger radial turbine.© 2014 ASME