检索结果-南通市图书馆

Effects of Perforation Number of Blade on Aerodynamic Performance of Dual-rotor Small Axial Flow Fans

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2015年第2期24卷 123-130页

作者： HU Yongjun WANG Yanping LI Guoqi JIN Yingzi Toshiaki Setoguchi heuy dong kim The Zhejiang Provincial Key Laboratory of Fluid Transmission Technology Zhejiang Sci-Tech University Department of Mechanical Engineering Saga UniversityHonjo-machiSaga840-8502Japan School of Mechanical Engineering Andong National UniversitySeongcheon-Dong1375Gyeongdong-RDAndongGyeongsangnuk-DO760-749Korea

Compared with single rotor small axial flow fans, dual-rotor small axial flow fans is better regarding the static characteristics. But the aerodynamic noise of dual-rotor small axial flow fans is worse than that of single rotor small axial flow fans. In order to improve aerodynamic noise of dual-rotor small axial flow fans, the pre-stage blades with different perforation numbers are designed in this research. The RANS equations and the standard k-e turbulence model as well as the FW-H noise model are used to simulate the flow field within the fan. Then, the aerodynamic performance of the fans with different perforation number is compared and analyzed. The results show that：（1） Compared to the prototype fan, the noise of fans with perforation blades is reduced. Additionally, the noise of the fans decreases with the increase of the number of perforations. （2） The vorticity value in the trailing edge of the pre-stage blades of perforated fans is reduced. It is found that the vorticity value in the trailing edge of the pre-stage blades decreases with the increase of the number of perforations. （3） Compared to the prototype fan, the total pressure rising and efficiency of the fans with perforation blades drop slightly.

关键词： dual-rotor small axial flow fans the blade with perforation perforation number aerodynamic per-formance

A Study of the Vortical Flow over a Delta Wing with a Leading Edge Extension

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2003年第4期12卷 299-303页

作者： heuy-dong kim Young-Ki Lee Tae-Ho kim Myoung-Hwan Sohn School of Mechanical Engineering Andong National University Andong 760-749 KoreaSchool of Mechanical Engineering Andong National University Andong 760-749 KoreaSchool of Mechanical Engineering Andong National University Andong 760-749 KoreaDepartment of Aerospace Engineering Korean Air Force Academy Chongwon-gun ChungBook-Do 363-849 Korea

The present paper describes computational and experimental work on the vortex flow characteristics of a sharp-edged delta wing with a leading edge extension (LEX). Experiment was carried out using a low-speed wind tunnel that has a test section of 3.5 m(W)×2.45 m(H)×8.7 m(L). The angle of attack of the delta wing ranges from 10° to 30°. The free stream velocity is fixed at 20 m/s, which corresponds to Reynolds number of 0.88×106. Computations using the mass-averaged implicit 3D Navier-Stokes equations were applied to predict the complicated vortical flow over the delta wing. The governing equations were discretized in space using a fully implicit finite volume differencing formation. The standard k-e turbulent model was employed to close the governing equations. The present computations predicted the experimented flow field with a good accuracy.

关键词： delta wing leading edge extension (LEX) vortex core vortex strength.

Computational study on flow through truncated conical plug nozzle with base bleed

在线全文

学校读者我要写书评

暂无评论

Propulsion and Power Research 2019年第2期8卷 108-120页

作者： Prasanth P.Nair Abhilash Suryan heuy dong kim Department of Mechanical Engineering College of Engineering TrivandrumTrivandrum 695016India Department of Mechanical Engineering Andong National UniversityAndong 760749Republic of Korea

Conical plug nozzle and truncated conical plug nozzle are advanced rocket nozzles suitable for use as altitude compensating *** this study flow through the conical plug and truncated conical plug nozzles are numerically simulated to first validate with experimental data and then to compare the performance when a base bleed is *** numerical analysis has considered two-dimensional axisymmetric ***-averaged NavierStokes equations are solved with two equation shear stress transport k-ω turbulence *** the validation of the plug nozzle,flow features and wall pressure along the length of the nozzle is taken for different nozzle pressure *** the validation of truncated plug nozzle,flow features and base pressures at various nozzle pressure ratios are *** base bleed is taken as 2%of the inlet mass flow *** comparison of results shows that the introduction of base bleed helps to compensate for the loss of thrust due to conical plug nozzle truncation.

关键词： Plug nozzle Aerospike nozzle Advanced rocket nozzle Reynolds-averaged Navier-Stokes(RANS) Base pressure Coefficient of thrust Base bleed Secondary flow

Mass Flow Prediction of the Coriolis Meter using C^0 Continuous Beam Elements

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2015年第4期24卷 398-402页

作者： Binulal B R Akash Rajan Abhilash Suryan R Jayaraj Kochupillai heuy dong kim Research Scholar Department of Mechanical EngineeringCollege of Engineering Trivandrum Department of Mechanical Engineering College of Engineering Adoor Department of Mechanical Engineering College of Engineering Trivandrum Department of Mechanical Engineering Andong National University

A three node C^0 continuous isoparametric beam element is formulated to model the curved pipe conveying fluid in three dimensional *** equations of motion for the combined structure and fluid domain including added mass effect,Coriolis effect,centrifugal effect and the effect of pressure on the walls of pipe have been developed by *** equation is converted to finite element formulation using Galerkin technique and is validated with the results available from literature.

关键词： Coriolis mass flow meter Timoshenko beams finite element formulation Coriolis effect

Effect of Non-Equilibrium Condensation of Moist Air on Unsteady Behaviour of Shock Waves around a Circular Arc Blade

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2007年第2期16卷 134-139页

作者： Shigeru MATSUO Kenbu TERAMOTO Miah MD.Ashraful ALAM Toshiaki SETOGUCHI heuy dong kim Shen YU Department of Mechanical Engineering Saga University1Honjo-machiSaga-shiSaga 840-8502Japan Department of Mechanical Engineering Khulna University of Engineering & TechnologyKhulna-9203Bangladesh School of Mechanical Engineering Andong National University388Songchun-dongAndong 760749Korea Institute of Engineering Thermophysics Chinese Academy of SciencesP.O.Box 2706Beijing 100080China

The unsteady phenomena in the transonic flow around airfoils are observed in the flow field of fan, compressor blades and butterfly valves, and this often causes serious problems such as the aeroacoustic noise, the vibration. In the transonic or supersonic flow where vapour is contained in the main flow, the rapid expansion of the flow may give rise to a non-equilibrium condensation. However, the effect of non-equilibrium condensation on the transonic internal flows around the airfoil has not yet been clarified satisfactorily. In the present study, the effect of non-equilibrium condensation of moist air on the self-excited shock wave oscillation on a circular arc blade was investigated numerically. The results showed that in the case with non-equilibrium condensation, frequencies of the flow oscillation became smaller than those without the non-equilibrium condensation.

关键词： compressible flow transonic flow shock wave oscillation non-equilibrium condensation simulation

Analysis of choked two-phase flows of gas and particle in a C-D nozzle

在线全文

学校读者我要写书评

暂无评论

Theoretical & Applied Mechanics Letters 2017年第6期7卷 331-338页

作者： Guang Zhang heuy dong kim Ying Zi Jin Department of Mechanical Engineering Andong National University College of Mechanical Engineering & Automation Zhejiang Sci-Tech University

Particle-gas two-phase flows show significantly different behaviors compared to single gas flow through a convergent-divergent nozzle. Non-equilibrium effects, thermal and velocity lag results to the inefficiency of nozzle performance. In the present studies, theoretical analysis and numerical simulations were carried out to investigate particle-gas flows in a C-D nozzle. Homogeneous equilibrium model that no lag in velocity and temperature occurs between particles and gas phase was used to derive mass flow rate and sound speed of multiphase flows. Two-phase flows are regarded as isentropic flows that isentropic relations can be used for homogeneous equilibrium model. Discrete phase model （DPM） where interaction with continuous phase and discrete random walk model were considered was used to calculate particle- gas flows. Particle mass loadings were varied to investigate their effects on choking phenomena of particle-gas flows. Mass flow rate and sound speed of mixture flows were theoretically calculated by homogeneous equilibrium model and compared with numerical results. Shock wave structure and particle number density were also obtained to be different at different particle mass loading and operating pressure conditions.

关键词： Multiphase flows Particle number density Shock wave Sound speed of mixture Flow choking

Hysteretic Phenomenon of Shock Wave in a Supersonic Nozzle

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第6期19卷 526-532页

作者： Toshiaki Setoguchi Shigeru Matsuo M.M. Ashraful Alam Junji Nagao heuy dong kim Institute of Ocean Energy Saga University Department of Advanced Technology Fusion Saga University Graduate School of Science & Engineering Saga University School of Mechanical Engineering Andong National University

In recent years, hysteretic phenomena in fluid flow systems drew attention for their great variety of industrial and engineering applications. When the high-pressure gas is exhausted to atmosphere from the nozzle exit, the expanded supersonic jet with the Mach disk is formed at a specific condition. In two-dimensional expanded supersonic jet, the hysteresis phenomenon for the reflection type of shock wave is occurred under the quasi-steady flow and the transitional pressure ratio between the regular reflection and Mach reflection is affected by this phe- nomenon. However, so far, there are very few researches for the hysteretic phenomenon of shock wave in a supersonic internal flow and the phenomenon has not been investigated satisfactorily. The present study was concemed with the experimental and numerical investigations of hysteretic phenomena of shock wave in a supersonic nozzle, and discussed the relationship between hysteresis phenomenon and rate of the change of pressure ratio with time.

关键词： compressible flow hysteresis internal flow shock wave supersonic nozzle

Effect of Annular Slit Geometry on Characteristics of Spiral Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2003年第3期12卷 225-230页

作者： Shigeru Matsuo Kwon-Hee Lee Shinsuke Oda Toshiaki Setoguchi heuy-dong kim Department of Mechanical Engineering Saga University 1 Honjo-machi Saga-shi Saga 840-8502Japan School of Mechanical Engineering College of Natural Science Andong National University388 Song-Cheon Dong Andong Kyung-Pook Korea

A spiral flow using an annular slit connected to a conical cylinder does not need special device to generate a tangential velocity component of the flow and differs from swirling flows. Pressurized fluid is supplied to an annular chamber and injected into the convergent nozzle through the annular slit. The annular jet develops into the spiral flow. In the present study, a spiral jet discharged out of nozzle exit was obtained by using a convergent nozzle and an annular slit set in nozzle inlet, and the effect of annular slit geometry on characteristics of the spiral jet was investigated by using a Laser Doppler Velocimeter (LDV) experimentally. Furthermore, velocity distributions of the spiral jet were compared with those of a normal jet.

关键词： spiral jet flow convergent nozzle annular slit LDV

Effect of Nozzle Inlet Shape on Annular Swirling Flow with Non-Equilibrium Condensation

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2015年第4期24卷 344-349页

作者： Yusuke FUKUSHIMA Shigeru MATSUO Toshiaki SETOGUCHI Norimasa SHIOMI Tokitada HASHIMOTO heuy dong kim and Shen YU Graduate School of Science & Engineering Saga University Department of Advanced Technology Fusion Saga University Institute of Ocean Energy Saga University Department of Mechanical Engineering Saga University School of Mechanical Engineering Andong National University Institute of Engineering Thermophysics Chinese Academy of Science

Recently,by combining a swirl flow with non-equilibrium condensation phenomena of condensate gas generated in a supersonic flow,a separating and extracting techniques of condensate gas have been *** technique can reduce the size of the device and don't use *** the present study,by using a non-equilibrium condensation phenomenon of moist air occurred in the supersonic flow in the annular nozzle composed of an inher body and an outer nozzle with a swirl,the possibility of separation of the condensable gas and the effect of shape of nozzle inlet on the flow field were examined numerically.

关键词： compressible flow non-equilibrium condensation supersonic annular nozzle swirl flow simulation