Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass rat...Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.展开更多
Military petroleum equipment, as the special device a nd tool for petroleum storage, transportation, filling, chemical analysis, detec tion and maintenance for the army, is an important means and basis of petroleum in...Military petroleum equipment, as the special device a nd tool for petroleum storage, transportation, filling, chemical analysis, detec tion and maintenance for the army, is an important means and basis of petroleum indemnificatory. To adapt to modern war in high-tech conditions, the petroleum equipment have to develop towards higher reliability, adaptability, maneuverabil ity, standardization, container and cell type with versatile multi-functions. As a new design theory and design process, concurrent engineering may prod uce remarkable benefit when applying to product development. With the aid of the state-of-the-art modeling and simulation technology, it foresees the future or even the whole life cycle of the products designed. Based on wide statistics and survey, the product design period is reduced by 1/2～1/3 with concurrent des i gn process. The application of concurrent design process in new petroleum equi pment development shall greatly accelerate the petroleum equipment updating an d promote their indemnificatory.展开更多
文摘Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design.
文摘Military petroleum equipment, as the special device a nd tool for petroleum storage, transportation, filling, chemical analysis, detec tion and maintenance for the army, is an important means and basis of petroleum indemnificatory. To adapt to modern war in high-tech conditions, the petroleum equipment have to develop towards higher reliability, adaptability, maneuverabil ity, standardization, container and cell type with versatile multi-functions. As a new design theory and design process, concurrent engineering may prod uce remarkable benefit when applying to product development. With the aid of the state-of-the-art modeling and simulation technology, it foresees the future or even the whole life cycle of the products designed. Based on wide statistics and survey, the product design period is reduced by 1/2～1/3 with concurrent des i gn process. The application of concurrent design process in new petroleum equi pment development shall greatly accelerate the petroleum equipment updating an d promote their indemnificatory.
文摘为使大推力航空并联混合动力推进系统在考虑节能减排效益的同时,充分挖掘涡轮电气化后部件的性能提升潜力,本文依托某并联混合动力齿轮传动涡扇发动机(Parallel hybrid geared turbofan,PH-GTF)推进系统概念模型,在“发动机主燃油闭环+电动力系统转矩补偿”控制结构下,针对典型飞行航程所包括的低功率工况段、起飞爬升段、巡航段、下降段,分别设计了相应的能量管理策略,并基于不同飞行工况在全航程内进行调度。通过典型飞行航线下的数字仿真及硬件在环(Hardware in the loop,HIL)仿真验证,结果表明,相较于未采用混合动力改型的基线GTF发动机,应用所设计综合全航程能量管理策略的PH-GTF推进系统,该航线下总燃油消耗量和NO_(x)排放量分别降低5.70%和10.72%,其中在低功率工况下,可变放气活门(Variable bleed valve,VBV)可以减小54.35%的排气量;在航空节能减排所重点关注的等高等速巡航段,耗油量和NO_(x)排放量分别降低18.93%和30.19%。所设计综合全航程能量管理策略兼顾了部件性能提升和节能减排效益,符合未来绿色航空推进系统的设计理念。
