In order to obtain optimized flight vehicle concepts which meet system of systems （SOS） operation requirements, designers have to pay high attention to the impact of SoS at conceptual design stage since operation en...In order to obtain optimized flight vehicle concepts which meet system of systems （SOS） operation requirements, designers have to pay high attention to the impact of SoS at conceptual design stage since operation environment goes increasingly complex. Based on this tendency, per- spectives and progre,;ses of SoS oriented flight vehicle conceptual design, which is abbreviate as SoSed design, are reviewed in this paper. Such basic concepts of SoS as definition, characteristics, differences between systems engineering and SoS engineering, as well as SoSed design process are introduced, then SoS engineering process model for research and development of flight vehicles and SoSed design wheel model for conceptual design are proposed. Related literature is classified and analyzed in accordance with four major elements including requirements, design concept, design analysis, and trade studies and optimization： typical SoS architectures, description and quan- tization of indexes are introduced; Application of inverse design in designing concept is analyzed; Modeling and simulation （M＆S）-based methods and their applications in SoSed effectiveness evaluation are highlighted; According to SoSed trade studies and optimization related research, the importance of such points as decision-making and using multidisciplinary design optimization for reference are emphasized. Finally, the value of SoSed design is concluded, and five directions which are worthy of .attention in this field are presented.展开更多
Three-dimensional numerical simulation is carried out to investigate the flow and heat transfer characteristics of impingement/effusion cooling systems. The impingement/effusion holes are arranged on two parallel perf...Three-dimensional numerical simulation is carried out to investigate the flow and heat transfer characteristics of impingement/effusion cooling systems. The impingement/effusion holes are arranged on two parallel perforated plates respectively in a staggered manner. Every effusion hole has an inclined angle of 30° with respect to the surface. The two parallel plates are spaced three times the diameter of the effusion hole. The ratio of center-to-center spacing of adjacent holes to the diameter of the effusion hole is set to be 3.0, 4.0 and 5.0 respectively. The flow field, temperature field and wall film cooling effectiveness are calculated for different blowing ratios ranging from 0.5 to 1.5. In general, the wall cooling effectiveness increases as the center-to-center spacing of adjacent holes decreases or the blowing ratio increases.展开更多
A series of computations is conducted for many multi-hole arrangements at several blowing ratios to further investigate the evolution of the film from multi-holes. The influence of multi-hole arrangement on effusion f...A series of computations is conducted for many multi-hole arrangements at several blowing ratios to further investigate the evolution of the film from multi-holes. The influence of multi-hole arrangement on effusion film cooling is analyzed and a preliminary relationship evaluating the film development from developing state to developed state is brought forward. Results show that the coolant jets from front rows of multi-holes merge rapidly and the strength of the kidney vortices due to mainstream-coolant jet interaction in the downstream region are mitigated under super-long-diamond arrangement where the streamwise hole-to-hole pitch is bigger than spanwise hole-to-hole pitch. The holes array arranged in super-long-diamond mode is not only in favor of obtaining developed film layer, but also improving averaged adiabatic film cooling effectiveness.展开更多
Greenhouse gas emission regulation and renewable energy promotion policies have been implemented in many countries.Yet these two kinds of regulation policies have complex interactions between each other,and can either...Greenhouse gas emission regulation and renewable energy promotion policies have been implemented in many countries.Yet these two kinds of regulation policies have complex interactions between each other,and can either enhance or reduce the overall emission reduction efficiency.If not well tuned,these regulation policies may deviate from their original intention and lead to unnecessary social cost.Hence,the policy effectiveness,cost effectiveness,and dynamic efficiency of different policy mixtures between emission trading and renewable energy subsidy are studied based on a novel dynamic simulation platform of power economy and power system.Simulation results show that these two kinds of regulation policy can coexist,but a good coordination between the emission trading and the renewable energy subsidy can achieve better emission reduction outcomes.展开更多
基金supported by the Fundamental Research Funds for the Central Universities of China
文摘In order to obtain optimized flight vehicle concepts which meet system of systems （SOS） operation requirements, designers have to pay high attention to the impact of SoS at conceptual design stage since operation environment goes increasingly complex. Based on this tendency, per- spectives and progre,;ses of SoS oriented flight vehicle conceptual design, which is abbreviate as SoSed design, are reviewed in this paper. Such basic concepts of SoS as definition, characteristics, differences between systems engineering and SoS engineering, as well as SoSed design process are introduced, then SoS engineering process model for research and development of flight vehicles and SoSed design wheel model for conceptual design are proposed. Related literature is classified and analyzed in accordance with four major elements including requirements, design concept, design analysis, and trade studies and optimization： typical SoS architectures, description and quan- tization of indexes are introduced; Application of inverse design in designing concept is analyzed; Modeling and simulation （M＆S）-based methods and their applications in SoSed effectiveness evaluation are highlighted; According to SoSed trade studies and optimization related research, the importance of such points as decision-making and using multidisciplinary design optimization for reference are emphasized. Finally, the value of SoSed design is concluded, and five directions which are worthy of .attention in this field are presented.
基金National Natural Science Foundation of China (50876041)Aeronautical Science Foundation of China (2008ZB2014)
文摘Three-dimensional numerical simulation is carried out to investigate the flow and heat transfer characteristics of impingement/effusion cooling systems. The impingement/effusion holes are arranged on two parallel perforated plates respectively in a staggered manner. Every effusion hole has an inclined angle of 30° with respect to the surface. The two parallel plates are spaced three times the diameter of the effusion hole. The ratio of center-to-center spacing of adjacent holes to the diameter of the effusion hole is set to be 3.0, 4.0 and 5.0 respectively. The flow field, temperature field and wall film cooling effectiveness are calculated for different blowing ratios ranging from 0.5 to 1.5. In general, the wall cooling effectiveness increases as the center-to-center spacing of adjacent holes decreases or the blowing ratio increases.
基金National Natural Science Foundation of China (50876041)
文摘A series of computations is conducted for many multi-hole arrangements at several blowing ratios to further investigate the evolution of the film from multi-holes. The influence of multi-hole arrangement on effusion film cooling is analyzed and a preliminary relationship evaluating the film development from developing state to developed state is brought forward. Results show that the coolant jets from front rows of multi-holes merge rapidly and the strength of the kidney vortices due to mainstream-coolant jet interaction in the downstream region are mitigated under super-long-diamond arrangement where the streamwise hole-to-hole pitch is bigger than spanwise hole-to-hole pitch. The holes array arranged in super-long-diamond mode is not only in favor of obtaining developed film layer, but also improving averaged adiabatic film cooling effectiveness.
基金This work was jointly supported by the Major Projects on Planning and Operation Control of Large Scale Grid,State Grid Corporation of China(SGCC-MPLG001-2012)State Grid EPRI Project(YS11002)the National Natural Science Foundation of China(91024028).
文摘Greenhouse gas emission regulation and renewable energy promotion policies have been implemented in many countries.Yet these two kinds of regulation policies have complex interactions between each other,and can either enhance or reduce the overall emission reduction efficiency.If not well tuned,these regulation policies may deviate from their original intention and lead to unnecessary social cost.Hence,the policy effectiveness,cost effectiveness,and dynamic efficiency of different policy mixtures between emission trading and renewable energy subsidy are studied based on a novel dynamic simulation platform of power economy and power system.Simulation results show that these two kinds of regulation policy can coexist,but a good coordination between the emission trading and the renewable energy subsidy can achieve better emission reduction outcomes.
