为了降低标准阶背式MIRA(Motor Industry Research Association)模型的气动阻力,设计了四种仿生非光滑单元体:仿生树叶菱形凸台、仿生海螺状凸台、仿生贝壳凹槽、仿生鱼尾楔形凸台。采用正交试验法,系统分析了这些单元体的安装位置、安...为了降低标准阶背式MIRA(Motor Industry Research Association)模型的气动阻力,设计了四种仿生非光滑单元体:仿生树叶菱形凸台、仿生海螺状凸台、仿生贝壳凹槽、仿生鱼尾楔形凸台。采用正交试验法,系统分析了这些单元体的安装位置、安装间距、形状、高度和宽度对气动性能的影响。结果表明:影响减阻效果主次因素为非光滑单元体安装位置,安装间距、形状、高度和宽度;最优组合为在车尾安装仿生楔形鱼尾凸台(高度为11 mm,宽度为21 mm,间距为50 mm),其阻力系数(C_(D))为0.2950,相较于原MIRA模型减阻率达到了9.006%。流场分析表明,最优组合非光滑单元体能够增加MIRA模型尾部分离区流场的能量,减小尾涡面积,有效降低气动阻力。展开更多
为解决当前汽车气动减阻研究中非光滑表面布置区域选取的盲目性和单一性的问题,作者以阶梯背式MIRA模型为研究对象,通过离散伴随法确定了模型的风阻系数高灵敏度区域,随后在上述区域分别布置了4种不同形状的非光滑表面,通过数值计算确...为解决当前汽车气动减阻研究中非光滑表面布置区域选取的盲目性和单一性的问题,作者以阶梯背式MIRA模型为研究对象,通过离散伴随法确定了模型的风阻系数高灵敏度区域,随后在上述区域分别布置了4种不同形状的非光滑表面,通过数值计算确定每个区域的非光滑单元体的最佳形状。为了减少汽车的气动阻力,采用优化拉丁超立方抽样方法进行试验设计(design of experiments, DOE),采用Kriging空间插值法来建立近似模型,使用优化算法对近似模型进行综合优化。结果表明,相较于原模型,优化模型风阻系数减少3.22%。该研究为汽车非光滑表面气动减阻和优化提供了理论依据和参考。展开更多
Marine fouling is a worldwide problem,which is harmful to the global marine ecological environment and economic benefits.The traditional antifouling strategy usually uses toxic antifouling agents,which gradually expos...Marine fouling is a worldwide problem,which is harmful to the global marine ecological environment and economic benefits.The traditional antifouling strategy usually uses toxic antifouling agents,which gradually exposes a serious environmental problem.Therefore,green,long-term,broad-spectrum and eco-friendly antifouling technologies have been the main target of engineers and researchers.In recent years,many eco-friendly antifouling technologies with broad application prospects have been developed based on the low toxicity and non-toxicity antifouling agents and materials.In this review,contemporary eco-friendly antifouling technologies and materials are summarized into bionic antifouling and non-bionic antifouling strategies(2000-2020).Non-bionic antifouling technologies mainly include protein resistant polymers,antifoulant releasing coatings,foul release coatings,conductive antifouling coatings and photodynamic antifouling technology.Bionic antifouling technologies mainly include the simulated shark skin,whale skin,dolphin skin,coral tentacles,lotus leaves and other biology structures.Brief future research directions and challenges are also discussed in the end,and we expect that this review would boost the development of marine antifouling technologies.展开更多
文摘为了降低标准阶背式MIRA(Motor Industry Research Association)模型的气动阻力,设计了四种仿生非光滑单元体:仿生树叶菱形凸台、仿生海螺状凸台、仿生贝壳凹槽、仿生鱼尾楔形凸台。采用正交试验法,系统分析了这些单元体的安装位置、安装间距、形状、高度和宽度对气动性能的影响。结果表明:影响减阻效果主次因素为非光滑单元体安装位置,安装间距、形状、高度和宽度;最优组合为在车尾安装仿生楔形鱼尾凸台(高度为11 mm,宽度为21 mm,间距为50 mm),其阻力系数(C_(D))为0.2950,相较于原MIRA模型减阻率达到了9.006%。流场分析表明,最优组合非光滑单元体能够增加MIRA模型尾部分离区流场的能量,减小尾涡面积,有效降低气动阻力。
文摘为解决当前汽车气动减阻研究中非光滑表面布置区域选取的盲目性和单一性的问题,作者以阶梯背式MIRA模型为研究对象,通过离散伴随法确定了模型的风阻系数高灵敏度区域,随后在上述区域分别布置了4种不同形状的非光滑表面,通过数值计算确定每个区域的非光滑单元体的最佳形状。为了减少汽车的气动阻力,采用优化拉丁超立方抽样方法进行试验设计(design of experiments, DOE),采用Kriging空间插值法来建立近似模型,使用优化算法对近似模型进行综合优化。结果表明,相较于原模型,优化模型风阻系数减少3.22%。该研究为汽车非光滑表面气动减阻和优化提供了理论依据和参考。
基金The authors are grateful for grants received from the National Natural Science Foundation of China(Grant No.51875240)the Jilin Provincial Science and Tcchnology Developmcnt Plan,Young and Middle-Tech Leading Talent and Team Project(Grant No.20200301013RQ)+1 种基金the Department of Science and Technology of Jilin Province(Grant No.20190103114JH)Key Laboratory Fund of National Defense Science and Technology(Grant No.6142005190201).
文摘Marine fouling is a worldwide problem,which is harmful to the global marine ecological environment and economic benefits.The traditional antifouling strategy usually uses toxic antifouling agents,which gradually exposes a serious environmental problem.Therefore,green,long-term,broad-spectrum and eco-friendly antifouling technologies have been the main target of engineers and researchers.In recent years,many eco-friendly antifouling technologies with broad application prospects have been developed based on the low toxicity and non-toxicity antifouling agents and materials.In this review,contemporary eco-friendly antifouling technologies and materials are summarized into bionic antifouling and non-bionic antifouling strategies(2000-2020).Non-bionic antifouling technologies mainly include protein resistant polymers,antifoulant releasing coatings,foul release coatings,conductive antifouling coatings and photodynamic antifouling technology.Bionic antifouling technologies mainly include the simulated shark skin,whale skin,dolphin skin,coral tentacles,lotus leaves and other biology structures.Brief future research directions and challenges are also discussed in the end,and we expect that this review would boost the development of marine antifouling technologies.
