检索结果-南通市图书馆

施工技术 2011年第S2期40卷 336-340页

作者：魏宇青党建堂曹飞张帆西安交通大学基建处陕西西安710049 西安交通大学动力工程多相流国家重点实验室陕西西安710049

针对西安南洋大酒店提出一种利用太阳能真空管集热器改造天然气锅炉供热系统的工程设计方案。首先通过热力学理论建立供热系统的数理模型,利用TRNSYS仿真软件对系统性能进行了模拟,最后对其开展技术经济性可行性分析。

关键词：绿色节能太阳能集热器 TRNSYS仿真热水系统

Stability of stratified flow and slugging in horizontal gas-liquid flow

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第11期15卷 1026-1034页

作者： GU Hanyang and GUO Liejin (state key laboratory of multiphase flow in power engineering, xi’an jiaotong university, xi’an 710049, china) state key laboratory of multiphase flow in power engineering Xi''an Jiaotong University Xi''an 710049 China

A transient one-dimensional two-fluid model is proposed to investigate numerically the interfacial instability and the onset of slugging for liquid-gas flow in a horizontal duct. In the present model, the effects of surface tension and transverse variations in dynamic pressure are taken into account. The evolution of interfacial disturbances is displayed and compared with the linear viscous Kelvin-Helmholtz stability analyses. It shows that interfacial wave is more instable due to the non-linear effect. The model predicts well the stability limit of stratified flow in comparison with the experimental data, and also automatically tracks the onset of slugging. The results show that the initiation of hydrodynamic slugging is related to local interfacial instability. Based on the cycle of slugging, a model for slug frequency is presented, which predicts the trends of slug frequencies with gas/liquid flow rate well in comparison with the available data. The effects of physical properties on slugging have been examined. It is found that with the increase in the gas viscosity and liquid density the slugging would be inhibited, whereas, with the increase in liquid viscosity and gas density, the slugging can be promoted.

关键词： two-fluid model Kelvin-Helmholtz stability interfacial instability onset of slugging gas-liquid stratified flow.

Numerical Investigation of Developing Turbulent flow in a Helical Square Ductwith Large Curvature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2001年第1期10卷 1-6页

作者： Gao Hui,Guo Liejin (state key laboratory of multiphase flow in power engineering, xi’an jiaotong university, xi’an 710049, china ) state key laboratory of multiphase flow in power engineering Xi’an Jiaotong University Xi’an China

A fully elliptic numerical study has been carried out to investigate the three-dimensional turbulent developing flow in a helical square duct with large curvature. A two-layer zonal model is proposed and used, in which the whole region is divided into a viscosity-affected near wall layer and a fully turbulent region. A DSM closure is applied in the former, and a one-equation model is solved in the latter. The results presented in this paper cover a Reynolds number range of (l- 10) x 104. The development of flow is found to be dominated by radial pressure gradient and Dean-type secondary motion. The distribution of Reynolds stresses in fully developed flow exhibit a complex pattern of turbulence anisotropy The development of peripherally averaged friction factor and the distribution of local friction factor in fully developed flow are given and discussed.

关键词： curved pipe developing flow turbulence model numerical simulation.

Acoustic Wave Prediction in flowing Steam-Water Two-Phase Mixture

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1994年第3期3卷 147-154页

作者： Xu Jinliang Chen Tingkuan (state key laboratory of multiphase flow in power engineering, xi’an jiaotong university, xi’an 710049,china) 1. state key laboratory of multiphase flow in power engineering Xi’an Jiaotong University 710049 Xi’an China

The transient two-fluid model has been used to develop a general relation for acoustic waves. The analysis is valid in principle over the whole void fraction region. flow pattern transitions from one flow regime to the other are assumed to occur at certain void fractions. Different correlations are used to calculate the interfacial area and interfacial drag force per unit mixture volume for bubbly flow,slug flow and annular flow respectively. The Vapour-liquid interphase heat flux is derived from the one dimensional Fourier heat conduction equation to evaluate the interphase evaporation or condensatior *** on the present theory, a program has been carried out. Calculations are performed for pressure from 0.07 MPa to 16.0 MPa, void fractions from 0.0 to 1.0. The predicted sound speeds are compare with some experimental data for low pressures, good agreement has been achieved between sound speed predictions and experimental data.

关键词： two-phase flow perturbation wave sound speed

NUMERICAL SIMULATION OF WET STEAM CONDENSING flow WITH AN EULERIAN/EULERIAN MODEL

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical engineering 2003年第2期16卷 156-159页

作者： Li LiangFeng ZhenpingLi Guojunstate key laboratory of multiphase flowin power engineering,xi’ an jiaotong university,xi’ an 710049, china xi' an jiaotong university State Key Laboratory of Multiphase Flow in Power Engineering Xi'an 710049

Wet steam condensing flow in low-pressure steam turbine leads to efficiencylosses and blade erosions. In order to investigate this problem by numerical approach, anEulerian/Eulerian model has been developed, in which the wet steam is regarded as mixture comprisingtwo coupled systems: the vapor phase and the liquid phase. These two systems are both described byconservation equations. High resolution TVD scheme is employed to capture condensing phenomena inwet steam flow. This model has been validated by numerical simulations of condensing flows in 1D and2D nozzles. Compared with experimental data, a good agreement is observed. This Eulerian/Eulerianmodel can be extended to 3D calculation of condensing flow.

关键词： wet steam condensing flow numerical simulation eulerian/eulerian model

Numerical Simulation of Transient 3-D Turbulent Hested Jet into Crossflow in a Thick-Wall T-Junction Pipe

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2001年第1期10卷 46-51页

作者： Wu Hailing, Chen Tingkuan, Luo Yushan, Wang Haijun (state key laboratory of multiphase flow in power engineering,xi’an jiaotong university, xi’an 710049, china) state key laboratory of multiphase flow in power engineering Xi’an Jiaotong University Xi’an China

The present work is to investigate the transient three-dimensional heated turbulent jet into crossflow in a thickwall T-junction pipe using CFD package. Two cases with the jet-to-crossflow velocity ratio of 0.05 and 0.5 are computed, with a finite-volume method utilizing κ-ε model. Comparison of the steady-state computations with measured data shows good qualitative agreement. Transient process of injection is simulated to examine the thermal shock on the T-junction component. Temporal temperature of the component is acquired by thermal coupling with the fluid. Via analysis of the flow and thermal characteristics, factors causing the thermal shock are studied. Optimal flow rates are discussed to reduce the thermal shock.

关键词： numerical simulation low jet-to-crossflow velocity ratio thick-wall T-junction pipe thermal shock

Study on Thermo-Conductive Plastic Finned TubeRadiators

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1997年第1期6卷 21-26页

作者： Yang Jiehui Cheng Lixin(Chemical engineering School, state key laboratory of multiphase flow in power engineering, xi’anjiaotong university, xi’an 710049, china) Chemical engineering School State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an China

This paper discusses thermo-conductive plastic finned tube radiators used in water saving type powerstations. First, the development of thermo-conductive plastics is introduced. Second, in order todetermine the rational geometric dimensions of thermo-conductive plastic finned tubes, an objectivefunction which takes the minimum volume of the consumed material for making finned tubes as an ob-ject is introduced. On the basis of the function, the economy comparison between thermaxonductiveplastic finned tubes and metal finned tubes is conducted.

关键词： air-cooling radiator thermo-conductive plastic finned tube optimum geometric parameters economy comparison

Coordination of distinctive pesticide adjuvants and atomization nozzles on droplet spectrum evolution for spatial drift reduction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical engineering 2024年第2期66卷 250-262页

作者： Shidong Xue Jingkun Han xi xi Zhong Lan Rongfu Wen Xuehu Ma state key laboratory of Fine Chemicals Liaoning Key Laboratory of Clean Utilization of Chemical ResourcesInstitute of Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 16024China School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong Kong 999077China china Tianchen engineering Corporation Tianjin 300400China School of Energy and power engineering Dalian University of TechnologyDalian 116024China

Pesticide adjuvants,as crop protection products,have been widely used to reduce drift loss and improve utilization efficiency by regulating droplet ***,the coordinated regulation mechanisms of adjuvants and nozzles on droplet spectrum remain ***,we established the relationship between droplet spectrum evolution and liquid atomization by investigating the typical characteristics of droplet diameter distribution near the *** on this,the regulation mechanisms of distinctive pesticide adjuvants on droplet spectrum were clarified,and the corresponding drift reduction performances were quantitively evaluated by wind tunnel *** shows that the droplet diameter firstly shifts to the smaller due to the liquid sheet breakup and then prefers to increase caused by droplet *** the surface tension of sprayed liquid facilitates the uniform liquid breakup and increasing the viscosity inhibits the liquid deformation,which prolong the atomization process and effectively improve the droplet *** a result,the drift losses of flat-fan and hollow cone nozzles are reduced by about 50%after adding organosilicon and vegetable oil *** contrast,the air induction nozzle shows a superior anti-drift ability,regardless of distinctive *** findings provide insights into rational adjuvant design and nozzle selection in the field application.

关键词： Pesticide drift Spray droplets Particle size distribution Spray atomization Transport processes Adjuvants

Novel strengthening methods for ultralightweight sandwich structures with periodic lattice cores

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第3期53卷 875-877页

作者： LU TianJian 1 &ZHANG QianCheng 2 1 MOE key laboratory for Strength and Vibration,School of Aerospace,xi’an jiaotong university,xi’an 710049,china 2.state key laboratory for Mechanical Behavior of Materials,School of Material Science and engineering,xi’an jiaotong university,xi’an 710049,china 1. MOE key laboratory for Strength and Vibration School of Aerospace Xi’an Jiaotong University Xi’an 710049 China2. State Key Laboratory for Mechanical Behavior of Materials School of Material Science and Engineering Xi’an Jiaotong University Xi’an 710049 China

Recent development of ultralightweight lattice-cored sandwiches is reviewed,with focus placed on various novel fabrication methods introduced to strengthen these structures,covering not only research results published... 详细信息

关键词： cellular metals strengthening method fabrication sandwich panels

High-Quality Critical Heat Flux in Horizontally Coiled Tubes

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 1995年第3期4卷 205-211页

作者： Weimin Ma Mingyuan Zhang Xuejun Chen (state key laboratory of multiphase flow in power engineering, xi’an jiaotong universityt xi’an 710049, china) state key laboratory of multiphase flow in power engineering Xi’an Jiaotong University Xi’an China

An investigation on the high-quality dryout in two electrically heated coiled tubes with horizontally helix axes is reported. The temperature profiles both along the tube and around the circumference are measured, and it is found that the temperature profiles around the circumference are not idelltical for the cross-sections at different parts of the coil. The 'local condition hypothesis' seems applicable under present conditions, and the critical heat flux qcr decreases with increasing critical quality xcr The CHF increases as mass velocity and ratio of tube diameter to coil diameter (d/D) increases, and it seems not to be effected by the system pressure. The CHF is larger with coils than that with straight tubes, and the difference increases with increasing mass velocity and d/D.

关键词： horizoatally coiled tube critical heat flux.