Since the zero-net-mass-flux (ZNMF) jet was first used as a laboratory flow control method in 1990's, it has attracted much attention. The ZNMF jet has unique features such as compact actuator, no requirement for ...Since the zero-net-mass-flux (ZNMF) jet was first used as a laboratory flow control method in 1990's, it has attracted much attention. The ZNMF jet has unique features such as compact actuator, no requirement for external air supply, complex piping, etc., and becomes a hot topic research subject in fluid mechanics. This review introduces the state of the art in the development of ZNMF jet in the quiescent fluid, the interaction of the ZNMF jet with the cross flow and its application in the separation flow control. The evolution of the vortex ring/pair and the spacial flow structure of the ZNMF in quicent fluid or cross flow are presented, as well as the key parameter effects. At last, the applications of ZNMF jet in the wake control of the circular cylinder, the separation control on the airfoil and the aerodynamic force or moment control on MAV/UAV are presented.展开更多
Designing lighting for zero-net energy buildings poses unique and fascinating design problems.Beyond the challenge of providing lighting loads on the order of.1W/sqft2,these projects require toolsets beyond the typica...Designing lighting for zero-net energy buildings poses unique and fascinating design problems.Beyond the challenge of providing lighting loads on the order of.1W/sqft2,these projects require toolsets beyond the typical scope of a light-ing design consultant,including detailed controls design and photometric pre-dictions of available daylighting.These new roles are part of a broader trend in lighting design as,driven by new code requirements and a general push towards high-performing buildings,lighting design is becoming a more technical,metrics-driven profession.There’s a delicate balancing act here,and indeed we have the same responsibility to these projects as any other:lighting that is comfortable and functional for the occupants,that supports the architectural gesture,and that is available within the project budget.So the task is not simply to design the absolute minimum energy density(although yes,also that),but rather to identify ways in which all of these constraints may be harmonized,and embrace the collaborative and iterative workflow that these projects demand.This case study is written for architects,engineers,owners and others that want an overview of the lighting design process for ultra-low energy density buildings.I’ll gloss both the absolute basics and the more esoteric technical details in favor of discussing practical techniques that we used successfully to further the project goals,and the trade-offs we confronted.展开更多
基金the National Natural Science Foundation of China (Grant No. 10425207)the Aviation Creative Foundation of China (Grant No. 07A51001)
文摘Since the zero-net-mass-flux (ZNMF) jet was first used as a laboratory flow control method in 1990's, it has attracted much attention. The ZNMF jet has unique features such as compact actuator, no requirement for external air supply, complex piping, etc., and becomes a hot topic research subject in fluid mechanics. This review introduces the state of the art in the development of ZNMF jet in the quiescent fluid, the interaction of the ZNMF jet with the cross flow and its application in the separation flow control. The evolution of the vortex ring/pair and the spacial flow structure of the ZNMF in quicent fluid or cross flow are presented, as well as the key parameter effects. At last, the applications of ZNMF jet in the wake control of the circular cylinder, the separation control on the airfoil and the aerodynamic force or moment control on MAV/UAV are presented.
文摘Designing lighting for zero-net energy buildings poses unique and fascinating design problems.Beyond the challenge of providing lighting loads on the order of.1W/sqft2,these projects require toolsets beyond the typical scope of a light-ing design consultant,including detailed controls design and photometric pre-dictions of available daylighting.These new roles are part of a broader trend in lighting design as,driven by new code requirements and a general push towards high-performing buildings,lighting design is becoming a more technical,metrics-driven profession.There’s a delicate balancing act here,and indeed we have the same responsibility to these projects as any other:lighting that is comfortable and functional for the occupants,that supports the architectural gesture,and that is available within the project budget.So the task is not simply to design the absolute minimum energy density(although yes,also that),but rather to identify ways in which all of these constraints may be harmonized,and embrace the collaborative and iterative workflow that these projects demand.This case study is written for architects,engineers,owners and others that want an overview of the lighting design process for ultra-low energy density buildings.I’ll gloss both the absolute basics and the more esoteric technical details in favor of discussing practical techniques that we used successfully to further the project goals,and the trade-offs we confronted.
