This paper proposes a virtual brush model based on droplet operation to simulate Chinese calligraphy and traditional Chinese painting in real time. Two ways of applying droplet model to virtual calligraphy and paintin...This paper proposes a virtual brush model based on droplet operation to simulate Chinese calligraphy and traditional Chinese painting in real time. Two ways of applying droplet model to virtual calligraphy and painting are discussed in detail. The second droplet model is more elaborated and can produce more vivid results while being slightly more time-consuming. The novel feature of the proposed droplet virtual brush model successfully enables the simulation painting system to overcome the poor expressional ability of virtual brush based on particle system and avoids the complex evaluation of physical brush with solid model. The model, derived from the actual calligraphy and painting experience, due to the simplicity of the droplet operation and its powerful expressive ability, considerably improves the performance of the simulation system and maintains painting effect comparable with real brush by supporting special Chinese brush effect such as dry brush, feng and stroke diffusion.展开更多
In order to obtain good driving performance,a driving force model is presented for non-pneumatic elastic wheel.Brush model of pneumatic tyres is introduced and the deformations of elastic supports and tread are also t...In order to obtain good driving performance,a driving force model is presented for non-pneumatic elastic wheel.Brush model of pneumatic tyres is introduced and the deformations of elastic supports and tread are also taken into account.The longitudinal slip rate is redefined.The grounding pressure distribution of elastic wheels is analyzed and corrected according to speed,temperature and stiffness.Then rolling resistance equation is developed.Finally,simulation is conducted by software CarSim,and the results show that the estimated values are consistent with simulation values,especially at low longitudinal slip rate.The research can help to optimize design of non-pneumatic elastic wheel.展开更多
In order to better application of brush seal in rotating machinery,the leakage flow characteristics of the brush seal considering geometry effects are numerically analyzed using Reynolds-Averaged Navier-Stokes( RANS) ...In order to better application of brush seal in rotating machinery,the leakage flow characteristics of the brush seal considering geometry effects are numerically analyzed using Reynolds-Averaged Navier-Stokes( RANS) model coupling with a non-Darcian porous medium model. The reliability of the present numerical method is proved,which is in agreement with the experimental and numerical results from literatures. Three different bristle pack thicknesses,fence heights and initial clearances under different pressure ratios,rotational velocities and other operating conditions are utilized to investigate the effects of geometry modification on the brush seal leakage flow behaviors. It discusses the effectiveness of various geometry configurations outlining important flow features. The results indicate that the increase of fence height and clearance would lead to the increase of leakage rate. But the leakage is not linearly with respect to the bristle pack thickness,and the effect of rotational velocity is not obvious. Moreover,the detailed leakage flow fields and pressure distributions along the rotor surface,free bristle height,and fence height of the brush seals are also presented. The static pressure drop amplitude through the bristle pack and the pressure rise amplitude through the cavity would increase while the pressure differential increases. And the axial pressure is the main reason of bristle blow down. The results provide theoretical support for the brush seal structure optimal design.展开更多
为解决身管抽气孔边缘毛刺去除需求,根据磨料刷去除毛刺机理建立磨料刷加工载荷三要素理论计算模型,借助ABAQUS/CAE的扩展有限元法(Extend Finite Element Method,XFEM)分析载荷三要素对加工后残余毛刺的影响规律,通过响应面方差分析方...为解决身管抽气孔边缘毛刺去除需求,根据磨料刷去除毛刺机理建立磨料刷加工载荷三要素理论计算模型,借助ABAQUS/CAE的扩展有限元法(Extend Finite Element Method,XFEM)分析载荷三要素对加工后残余毛刺的影响规律,通过响应面方差分析方法得出三要素对结果影响程度由大到小依次为加载面积>加载方向>载荷大小,并由二阶回归方程计算出最优的载荷工况。通过所建立的模型联立求得最佳磨料刷加工工艺参数,并依据加工原理研制出专用装置进行加工实验,实现抽气孔边缘无毛刺的表面质量提升。展开更多
文摘This paper proposes a virtual brush model based on droplet operation to simulate Chinese calligraphy and traditional Chinese painting in real time. Two ways of applying droplet model to virtual calligraphy and painting are discussed in detail. The second droplet model is more elaborated and can produce more vivid results while being slightly more time-consuming. The novel feature of the proposed droplet virtual brush model successfully enables the simulation painting system to overcome the poor expressional ability of virtual brush based on particle system and avoids the complex evaluation of physical brush with solid model. The model, derived from the actual calligraphy and painting experience, due to the simplicity of the droplet operation and its powerful expressive ability, considerably improves the performance of the simulation system and maintains painting effect comparable with real brush by supporting special Chinese brush effect such as dry brush, feng and stroke diffusion.
基金supported by the Major Exploration Project of the General Armaments Department of China(NHA13002)the Funding of Jiangsu Innovation Program for Graduate Education+2 种基金the Fundamental Research Funds for the Central Universities of China(CXLX13_145)Jiangsu Province″333 Project″Training Funded Project(BRA2015365)the National Natural Science Foundation of Youth Fund Project(51305175,61503163)
文摘In order to obtain good driving performance,a driving force model is presented for non-pneumatic elastic wheel.Brush model of pneumatic tyres is introduced and the deformations of elastic supports and tread are also taken into account.The longitudinal slip rate is redefined.The grounding pressure distribution of elastic wheels is analyzed and corrected according to speed,temperature and stiffness.Then rolling resistance equation is developed.Finally,simulation is conducted by software CarSim,and the results show that the estimated values are consistent with simulation values,especially at low longitudinal slip rate.The research can help to optimize design of non-pneumatic elastic wheel.
基金Sponsored by the National Natural Science Foundation of China(Grant No.11272100)
文摘In order to better application of brush seal in rotating machinery,the leakage flow characteristics of the brush seal considering geometry effects are numerically analyzed using Reynolds-Averaged Navier-Stokes( RANS) model coupling with a non-Darcian porous medium model. The reliability of the present numerical method is proved,which is in agreement with the experimental and numerical results from literatures. Three different bristle pack thicknesses,fence heights and initial clearances under different pressure ratios,rotational velocities and other operating conditions are utilized to investigate the effects of geometry modification on the brush seal leakage flow behaviors. It discusses the effectiveness of various geometry configurations outlining important flow features. The results indicate that the increase of fence height and clearance would lead to the increase of leakage rate. But the leakage is not linearly with respect to the bristle pack thickness,and the effect of rotational velocity is not obvious. Moreover,the detailed leakage flow fields and pressure distributions along the rotor surface,free bristle height,and fence height of the brush seals are also presented. The static pressure drop amplitude through the bristle pack and the pressure rise amplitude through the cavity would increase while the pressure differential increases. And the axial pressure is the main reason of bristle blow down. The results provide theoretical support for the brush seal structure optimal design.
文摘为解决身管抽气孔边缘毛刺去除需求,根据磨料刷去除毛刺机理建立磨料刷加工载荷三要素理论计算模型,借助ABAQUS/CAE的扩展有限元法(Extend Finite Element Method,XFEM)分析载荷三要素对加工后残余毛刺的影响规律,通过响应面方差分析方法得出三要素对结果影响程度由大到小依次为加载面积>加载方向>载荷大小,并由二阶回归方程计算出最优的载荷工况。通过所建立的模型联立求得最佳磨料刷加工工艺参数,并依据加工原理研制出专用装置进行加工实验,实现抽气孔边缘无毛刺的表面质量提升。
