考虑鲁棒性的超临界翼型激波控制鼓包减阻研究

本文主要采用CFD方法研究超临界翼型的激波控制鼓包减阻技术,分析了鼓包形状参数对减阻效果和鲁棒性的影响规律.计算结果显示,鼓包的减阻效果受位置影响较大,当鼓包最高点与干净翼型的激波位置相同时减阻效果较好,鼓包高度过高对减阻效果不利,而较长的鼓包可在更大的高度范围内实现减阻.鼓包还可以通过弱化激波,抑制附面层分离,延缓超临界翼型抖振现象的发生.计算结果显示,鼓包减阻技术整体而言工作范围较窄.但经过设计,较长且较低的鼓包可以在较大的升力范围内具有减阻效果,并且减阻效果对形状变化及雷诺数变化不敏感,还能有效提高阻力发散马赫数,鲁棒性要明显优于较短较高的鼓包,具有工程应用的潜力.     

Numerical Investigation of Fire Smoke Transport in the Tsinghua University Sports Center

Fire Dynamics Simulator v3.0 was used to investigate and management in a realistic indoor sports center. An atrium fire test case assess fire smoke transport and ustrated the code＇s superiority over code-type empirical models for both accuracy and capability. Four fire scenarios in the Tsinghua University Sports Center were then simulated. The smoke layer＇s descent speed was predicted for each case. The importance of the door effect was revealed and an additional mechanical ventilation system for the building was proved to be of no help. The door effect must be carefully considered in future fire safety designs.     

战斗机无人机编组协同系统需求捕获与验证

战斗机-无人机编组协同(fighter-drone teaming, FDT)是人员-信息-物理-智能一体化的全新作战形态, 其系统需求捕获与验证方法尚没有工程先例和经验可循, 亟需正向探索和实践。在一般的基于模型的系统工程(model-based systems engineering, MBSE)方法基础上, 提出整体纳入跨装备协同要素、将分析模型和验证模型分开构建、同步考量逻辑行为与时空关系的捕获与验证策略, 以及适用于编组协同“任务场景构建-系统行为分析-需求映射定义-模型在环验证”的流程和具体方法, 进而以典型“二带二”对地FDT为例进行应用检验。检验结果表明, 该方法可满足工程总体多专业联合工作需要, 能够高效形成编组协同系统需求清单及相应的捕获与验证依据, 从而为后续的系统设计和实现确立清晰的开发目标和设计指导。