Turbofan engine intakes are designed to provide separation-free flow at the fan faceover a wide range of operating conditions. But at some off-design conditions, like at high flightspeeds and high angles of attack (Ao...Turbofan engine intakes are designed to provide separation-free flow at the fan faceover a wide range of operating conditions. But at some off-design conditions, like at high flightspeeds and high angles of attack (AoA), the aero engine intake may encounter flow separation.This boundary layer separation inside the nacelle inlet of an aircraft engine can lead to a largenumber of undesirable outcomes like reduction in fan efficiency, engine stall and high levels ofstress on the fan blades. Active flow control is a promising solution to reduce inlet boundarylayer separation and the associated fan-face flow distortion at such off-design conditions. Byblowing pressurized air into the intake near the separation point, the boundary layer is ener-gized and separation can be controlled. This study investigates the applicability of lip blowing,an active flow control technique, to control intake separation and flow distortion at the fan-face.First, intake separation was triggered in a 3D CFD model based on the NASA CommonResearch Model (CRM) using high AoA cases at cruise condition (Mach number 0.85, Massflow capture ratio w0.7) and the features of separated flow were analyzed. Thereafter, activeflow control was introduce to the intake in the form of two types of lip blowing, direct andpitched blowing. The efficacy of lip blowing at achieving separation control in an ultra highbypass ratio turbofan engine intake has been established through this study. The present paperalso examines the significance of blowing parameters like the type of blowing, blowing pres-sure ratio, and blowing slot dimension, at different angles of attack to identify the critical con-trol parameters. Our research successfully establishes proof of concept by demonstrating the feasibility of using lip blowing for separation control in aero-intakes, via numerical modelling.Furthermore, this study also provides crucial insights regarding the important variables to beconsidered for future experimental studies, and also for detailed studies covering a wider rangeof operating and blowing conditions.展开更多
目的探讨自我调节常识性模型(CSM)的研究热点及演变,以期为护理工作者从健康心理学角度改善患者健康相关结局提供更清晰的研究方向。方法检索1985年1月1日—2020年12月31日Web of Science核心合集数据库中与CSM相关的英文文献,采用VOSvi...目的探讨自我调节常识性模型(CSM)的研究热点及演变,以期为护理工作者从健康心理学角度改善患者健康相关结局提供更清晰的研究方向。方法检索1985年1月1日—2020年12月31日Web of Science核心合集数据库中与CSM相关的英文文献,采用VOSviewer 1.6.15软件绘制关键词密度、聚类和时间分布可视化图谱,同时运用CiteSpace 5.6.R5软件对突现词进行检测。结果最终纳入文献364篇,CSM研究年发文量和被引频次总体呈上升趋势。CSM研究热点主要集中在解释或干预患者的疾病感知,以期改善患者的自我管理、依从性、生活质量、焦虑、抑郁及心理痛苦,研究对象主要为癌症患者。基于CSM框架对社会支持和心理困扰进行探讨,利用Meta分析的方法进行总结可能是未来CSM研究工作中重要的部分。CSM研究在经历理论完善、广泛应用后目前正处于总结和深化阶段。结论CSM研究年发文量和被引频次总体呈上升趋势,已得到国内学者关注,但与国外相比仍存在较大差距。未来研究可探讨社会支持在个体患病后自我调节过程中的作用,并通过Meta分析探讨干预患者负性疾病感知的有效方法,以期改善患者健康结局。展开更多
文摘Turbofan engine intakes are designed to provide separation-free flow at the fan faceover a wide range of operating conditions. But at some off-design conditions, like at high flightspeeds and high angles of attack (AoA), the aero engine intake may encounter flow separation.This boundary layer separation inside the nacelle inlet of an aircraft engine can lead to a largenumber of undesirable outcomes like reduction in fan efficiency, engine stall and high levels ofstress on the fan blades. Active flow control is a promising solution to reduce inlet boundarylayer separation and the associated fan-face flow distortion at such off-design conditions. Byblowing pressurized air into the intake near the separation point, the boundary layer is ener-gized and separation can be controlled. This study investigates the applicability of lip blowing,an active flow control technique, to control intake separation and flow distortion at the fan-face.First, intake separation was triggered in a 3D CFD model based on the NASA CommonResearch Model (CRM) using high AoA cases at cruise condition (Mach number 0.85, Massflow capture ratio w0.7) and the features of separated flow were analyzed. Thereafter, activeflow control was introduce to the intake in the form of two types of lip blowing, direct andpitched blowing. The efficacy of lip blowing at achieving separation control in an ultra highbypass ratio turbofan engine intake has been established through this study. The present paperalso examines the significance of blowing parameters like the type of blowing, blowing pres-sure ratio, and blowing slot dimension, at different angles of attack to identify the critical con-trol parameters. Our research successfully establishes proof of concept by demonstrating the feasibility of using lip blowing for separation control in aero-intakes, via numerical modelling.Furthermore, this study also provides crucial insights regarding the important variables to beconsidered for future experimental studies, and also for detailed studies covering a wider rangeof operating and blowing conditions.
文摘目的探讨自我调节常识性模型(CSM)的研究热点及演变,以期为护理工作者从健康心理学角度改善患者健康相关结局提供更清晰的研究方向。方法检索1985年1月1日—2020年12月31日Web of Science核心合集数据库中与CSM相关的英文文献,采用VOSviewer 1.6.15软件绘制关键词密度、聚类和时间分布可视化图谱,同时运用CiteSpace 5.6.R5软件对突现词进行检测。结果最终纳入文献364篇,CSM研究年发文量和被引频次总体呈上升趋势。CSM研究热点主要集中在解释或干预患者的疾病感知,以期改善患者的自我管理、依从性、生活质量、焦虑、抑郁及心理痛苦,研究对象主要为癌症患者。基于CSM框架对社会支持和心理困扰进行探讨,利用Meta分析的方法进行总结可能是未来CSM研究工作中重要的部分。CSM研究在经历理论完善、广泛应用后目前正处于总结和深化阶段。结论CSM研究年发文量和被引频次总体呈上升趋势,已得到国内学者关注,但与国外相比仍存在较大差距。未来研究可探讨社会支持在个体患病后自我调节过程中的作用,并通过Meta分析探讨干预患者负性疾病感知的有效方法,以期改善患者健康结局。
