共查询到19条相似文献,搜索用时 93 毫秒
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《工程热物理学报》2010,(6)
设计搭建了太阳能热声发动机实验系统,它由双轴全自动跟踪菲涅尔透镜聚焦型集热器和小型化驻波热声发动机两大组件构成。分别对充注不同压力N_2、He、Ar三种工质的太阳能热声发动机的起振温度、起振时热声核温度分布、压力振幅进行了实验研究。结果表明,氮气、氦气和氩气在相同充气压力下,He起振温度最高,N_2起振温度最低;N_2在充气压力1.0 MPa时达到最低起振温度394.8℃,且其压力振幅对充气压力变化不敏感;Ar在充气压力1.0 MPa时达到最低起振温度418.2℃,且其压力振幅随着充气压力的升高而逐渐增加。实验结果为优化太阳能热声发动机系统的热力性能提供了实验依据。 相似文献
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针对热声发动机中复杂的起振、消振行为,在自行研制的"驻波型热声发动机试验平台"上,开展了工质类型、加热功率、充气压力等参数对热声发动机起振、消振行为的影响规律研究.试验结果表明:当采用纯氦气和90%氦气+10%氩气的混合气体时,系统存在一最佳的充气压力值,使起振温度和消振温度达到最低;而其余工质,其起振温度与消振温度均随着充气压力增加而逐渐提高;与此同时,由于加热功率对板叠热端温度影响较小,故采用板叠热端温度作为行为特性参数更为合理. 相似文献
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针对热声发动机起振过程中复杂的温度变化,在自行研制的"驻波型热声发动机试验平台"上,开展了在不同的工质类型、充气压力等试验工况下,热声发动机起振过程的轴向温度分布规律和变化特征的试验研究,试验结果表明:对于氮气、氩气而言,其系统温度动态特性规律基本一致,且热声核温度梯度和热声板叠温度梯度存在较明显的差别;而对于氦气,其系统温度动态特性不同于前两类气体,且热声核的温度梯度和热声板叠温度梯度的差别十分微弱,可见,不同的工质类型将直接影响到发动机起振过程系统温度的动态变化特性. 相似文献
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Thermoacoustic engines are the devices that convert thermal energy into acoustic energy without moving parts. The main objective of this study is to analyze the performance of a thermoacoustic prime mover measured in terms of onset temperature difference, frequency, and pressure amplitude by varying resonator, stack length, and plate thickness. From the experiments, it is observed that onset temperature difference and pressure amplitude increases with increase in resonator and stack length with minimum plate thickness, whereas the frequency increases with decrease in resonator and stack length with higher plate thickness. The experimental results are compared with simulated results via Design Environment for Low Amplitude Thermoacoustic Energy Conversion software (Los Alamos National Laboratory, Los Alamos, New Mexico, USA). 相似文献
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Thermoacoustic prime movers can generate pressure oscillation without any moving parts on self-excited thermoacoustic effect. The details of the numerical simulation methodology for thermoacoustic engines are presented in the paper. First, a four-port network method is used to build the transcendental equation of complex frequency as a criterion to judge if temperature distribution of the whole thermoacoustic system is correct for the case with given heating power. Then, the numerical simulation of a thermoacoustic-Stirling heat engine is carried out. It is proved that the numerical simulation code can run robustly and output what one is interested in. Finally, the calculated results are compared with the experiments of the thermoacoustic-Stirling heat engine (TASHE). It shows that the numerical simulation can agrees with the experimental results with acceptable accuracy. 相似文献
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Raspet R Slaton WV Hickey CJ Hiller RA 《The Journal of the Acoustical Society of America》2002,112(4):1414-1422
The theory of acoustic propagation in an inert gas-condensing vapor mixture contained in a cylindrical pore with wet walls and an imposed temperature gradient is developed. It is shown that the vapor diffusion effects in the mixture are analogous to the heat diffusion effects in the thermoacoustics of inert gases, and that these effects occur in parallel with the heat diffusion effects in the wet system. The vapor diffusion effects can be expressed in terms of the thermoviscous function F(lambda) used in the theory of sound propagation of constant cross-section tubes. As such, these results can be extended to any shape parallel-walled tube. The propagation equations predict that the temperature gradient required for onset of sound amplification in a wet-walled prime mover is much lower than the corresponding temperature gradient for an inert gas prime mover. The results of a measurement of the onset temperature of a simple demonstration prime mover in air with a dry stack and with a stack wetted with water provide a qualitative verification of the theory. 相似文献
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《Revue Generale de Thermique》1998,37(4):305-314
The present research focused on re-circulation and conversion of substance and energies for creating water environments of higher productivity and purification from the oceanic carbon and nitrogen cycle point of view. The application of distributed energies and integrated systems through the autonomous dispersion control of the environment is able to display the increase of the functions of living things and create the harmonized re-circulation of production and purification. As Japan is an island country, wave energy pumps and air-mixed jet pumps have been invented as distributed energy prime movers for these circulation systems. This paper summarizes our research and development programs and describes some current results of sea trials with prototypes. 相似文献
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热声发动机的起振过程是一个产生并维持自激振荡的过程, 研究热声自激振荡机理有助于进一步了解热声效应的实质. 根据热声网络理论, 建立了驻波热声发动机的整机网络. 将热声网络比拟成电网络, 利用厄米特式计算了输入热声网络的视在功流, 功流平衡对应自激, 在角频率虚部为零的情况下计算了热声发动机的阈值温度和运行频率. 结果表明, 计算值与实验值符合得较好, 充气压力与阈值温度和运行频率的耦合关系大致相同. 所得结论有助于进一步探究热声效应机理以及热声发动机系统的优化设计. 相似文献
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Alexis Larranaga 《理论物理通讯》2008,50(6):1341-1344
In this paper we study the first law of thermodynamics for the
(2+1)-dimensional rotating charged BTZ black hole considering a pair of
thermodynamical systems constructed with the two horizons of this
solution. We show that these two systems are similar to the right
and left movers of string theory and that the temperature associated
with the black hole is the harmonic mean of the temperatures associated
with these two systems. 相似文献
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J.H. Pitchford 《Journal of sound and vibration》1976,47(3):371-385
Light distillate liquid fuels have self-evident qualities for mobile use. It is therefore incumbent upon us not to squander such fuels in applications where heavier and less costly fuels can be used. In considering the most economical fuel for automotive use, consideration must always be given to the energy required in its production in the refinery: gasoline and gas oil are compared. Various fuels and a variety of types of prime movers and their potentials are reviewed as regards their advantages and disadvantages, and consideration is given to the urgent national importance of a programme of R & D work aimed specifically at the parallel and complementary optimization on economic grounds of possible fuels and engine types so that, looking ahead ten to twenty years, the greatest work output may be achieved from the lowest energy input. Consideration is also given to overall “fuel to wheel” efficiency as influenced by the engine/transmission relationship. 相似文献
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Jing Li Yinzhu Jiang Tianyu Ma Cong Lu Yongbing Xu Deren Yang Mi Yan 《Physica B: Condensed Matter》2012,407(24):4783-4786
γ′-Fe4N thin films were grown on MgO-buffered Si (1 0 0) by pulsed laser deposition technique. Different crystallographic orientations and in-plane magnetic anisotropies were achieved by varying the growth temperature of the MgO buffer layer. When the MgO buffer layer was grown at room temperature, the γ′-Fe4N film shows isotropic in-plane magnetic properties without obvious texture; while in-plane magnetic anisotropy was recorded for the γ′-Fe4N films deposited on a 600 °C-grown-MgO buffer due to the formation of a (1 0 0)-oriented biaxial texture. Such a difference in in-plane magnetic anisotropy is attributed to the epitaxial growth of γ′-Fe4N film on an MgO buffer with relaxed strain when the MgO layer was grown at a high temperature of 600 °C. 相似文献