共查询到20条相似文献,搜索用时 31 毫秒
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RP-3和RP-5煤油对飞机动力装置和燃油系统试飞的影响 总被引:1,自引:0,他引:1
RP-3号航空煤油是军用飞机和民航客机最为常用的燃料,但是舰载飞机通常使用RP-5号航空煤油,RP-5号煤油突出特点是密度大、闪点高。此外,两种燃油在成分、黏度、饱和蒸气压、比热容、导电率等方面有诸多差异。这些差异会对飞机重心、燃油系统通气增压、供油流动损失、燃烧热值等造成影响,分析这些影响对飞机试飞具有重要的价值。 相似文献
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航空发动机滑油散热器换热试验与计算 总被引:1,自引:0,他引:1
对某型涡扇发动机用燃-滑油散热器进行了试验研究,得出了燃-滑油散热器性能曲线,建立了利用所得的性能曲线的计算模型,计算得出燃油和滑油的出口温度,与实验测量值进行比较,结果显示二者吻合较好。该模型的建立为该型燃-滑油散热器选用和相关计算提供参考。 相似文献
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高压液压技术是未来飞机液压系统的主要发展趋势,由于损耗功率增加,系统温度变化将更加剧烈并影响飞行安全,因此,高压液压系统的热特性与热控制技术是未来飞机液压系统设计需要考虑的一个重要因素。以某高压液压能源系统为例,对液压能源系统的主要液压元件进行生热和散热机理分析。利用AMESim软件开展液压系统温度特性分析,权衡系统是否需要热交换器。结果表明:热交换器有效降低系统油液温度至安全温度内;同时,得到燃油-液压油热交换器位于不同位置、系统在不同飞行阶段下不同环境温度、机翼处管路引入冷气流等工况下温度变化趋势,为飞机高压液压能源系统热设计提供参考。 相似文献
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Jeong Ho Lee Soo Young Kang Tong Seop Kim 《Journal of Mechanical Science and Technology》2012,26(11):3733-3740
This paper presents models for simulating the operation of a polymer electrolyte membrane fuel cell (PEMFC) system and the results of the dynamic simulations. The entire system included a PEMFC stack and balance-of-plant components such as an air supply blower, a membrane humidifier, a fuel supply unit, and a heat management unit. Mathematical modeling for the computation of power generation and heat transfer of the PEMFC stack, the heat and mass transfer of the humidifier, and the energy transfer of the cooling system was set up. Theoretical and experiential data such as the voltage-current density relationship of the cell stack and the performance maps of blowers and pumps, together with semi-theoretical heat and mass transfer equations, were used to represent the characteristics of all the components. The effect of the thermal inertia of solid parts was considered in the fuel cell stack, the membrane humidifier, and the radiator. System dynamic behaviors under various operating conditions due to changes in stack current and ambient temperature were predicted. The sudden abnormal operations of the cooling water circulation pump and the radiator fan were also simulated as an example of component malfunctions. 相似文献
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Jae-Dol Kim Jung-In Yoon Hag-Geun Ku 《Journal of Mechanical Science and Technology》1997,11(2):221-228
An analysis of the dynamic characteristics in an evaporator was numerically performed for control and design of the refrigeration
and air conditioning systems. The important factors, such as refrigerant flow rate, inlet enthalpy, inlet air velocity and
air temperature, are incorporated with this analysis. An evaporator is modeled for the dynamic characteristics analysis separated
into three regions which are the two-phase region, the saturated vapor region and the superheated vapor region. The basic
equations of each region were derived in the continuity, heat energy equilibrium and heat transfer equations. The transfer
functions of the dynamic characteristics were obtained by the linearization and Laplace transformation. The dynamic response
characteristics were evaluated on the Bode diagram with the frequecy response method. These results may be used for the analysis
of the dynamic characteristics and design in the total system. 相似文献
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飞机在极端气候环境中飞行时,往往会引起飞机燃油系统结冰,使系统给发动机所供的燃油流量间歇中断或完全中断,从而导致飞行事故。因此,在当前新机研制中,对燃油系统的结冰问题加以重点考虑,并且不仅要在实验室对系统进行燃油结冰模拟试验,而且在型号试飞阶段也要模拟极端气候条件进行燃油系统结冰飞行试验,以便考核该条件下燃油系统供油能力和发动机工作可靠性。本文结合某型飞机燃油系统结冰试验技术攻关工作,研究飞机燃油系统结冰飞行试验的燃油配水方法和试验程序。 相似文献
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本文简述了飞机油箱通气增压系统的分类,介绍了封闭式油箱通气增压系统的原理,以典型闭式系统为例,分析了飞机在起飞、爬升、不同高度稳定平飞、加减速平飞、空中应急放油以及油箱增压输油等典型工况下油箱气压的变化规律,为后续飞机油箱通气增压系统的设计和试飞方法研究提供依据,具有很高的工程试验价值。 相似文献
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车用传动装置润滑系统的流动与传热仿真 总被引:1,自引:0,他引:1
提出了车用传动装置润滑系统流动与传热的稳态仿真模型。基于一维不可压缩流动方程,建立了润滑油流动的仿真模型;研究了传动润滑系统的传热机理,采用热网络法建立了润滑系统的传热模型;对某型坦克液力机械传动装置润滑系统的流动与传热进行了仿真,预测了润滑系统的流量、压力和温度分布,仿真结果与试验值基本吻合。本研究为车用传动装置润滑系统的流动与传热性能提供了一种有效的理论分析手段和仿真方法。 相似文献
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Jinkun Lee Inyoung Yang Sooseok Yang Jae Su Kwak 《Journal of Mechanical Science and Technology》2007,21(4):664-671
The altitude engine test is carried out to measure the performance of the engine of flight vehicle at the high altitude environment
prior to the flight test. During the test, The measured pressures and temperatures at various positions, air flow rate, fuel
flow rate, thrust of the engine are measured. These measured values are used to calculate the representative performance values
such as the net thrust and the specific fuel consumption. Hence each of the measured parameter has effects on the total uncertainly
of the performance values. In this paper, the combined standard uncertainties of the net thrust and the specific fuel consumption
were estimated from the uncertainties of the various measured values. Also, by estimating the repeatability and the reproducibility,
the confidence levels of the altitude engine test were validated by the analysis of variation on the repeated test data by
different tester groups. 相似文献
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高寒环境中,测试设备只能间断性地测量飞机油箱燃油温度,如果要获得温度连续变化的趋势,只能通过试验数据拟合的办法。本文以传热学理论为基础,以飞机油箱基本参数为条件,推导出了油箱油温变化的理论公式,并以此公式为指导来拟合温度变化趋势,所得的拟合方程与试验数据变化规律一致,且误差较小,表明机翼油箱油温变化符合自然指数形式的变化规律。另外,结合理论推导的数据拟合,工程实用性很强,具备较大的推广价值。 相似文献
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