Wind tunnel (WT) is a device that artificially produces airflow relative to a stationary body and measures aerodynamic force and pressure distribution, simulating the actual conditions with an important aspect of accurately feigning¬ the full complexity of fluid flow. The aim of the present study is to design the three dimensional geometry of a small, open-circuit (also known as Eiffel Type), and subsonic (low speed) wind tunnel (WT) capable of demonstrating or acting as a vital tool in aero-mechanics research. The project and fabrication itself, poses as an onerous task with the cynosure/central theme being the delineation/depiction of wind tunnel components such as Test Section, contraction cone, diffuser, drive system and settling chamber.
#1Feng Chen(Civil Aviation Administration of China)H-Index: 21
#2Haorong Peng(Civil Aviation Administration of China)H-Index: 2
Last. Xiaoqing Zeng(Civil Aviation Administration of China)H-Index: 2
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Abstract To study the effect of complex terrain on the wind characteristics of the glide paths at Hong Kong International Airport’s North Runway, wind tunnel testing was conducted in Tongji University’s TJ-3 boundary layer wind tunnel, and Cobra probes were used to measure the wind speed and wind direction at the North Runway glide paths. The effects of terrain on the wind characteristics, including turbulence intensity, turbulence integral scale, and mean headwind speed were analysed. The resul...
Last. Mircea Degeratu(Hong Kong Environmental Protection Department)H-Index: 3
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Abstract The aim of the study was to analyze and design through experimental and numerical investigations a passive device to control the development of the boundary layer in an existing short wind tunnel to reproduce conditions representative of an atmospheric boundary layer for wind engineering applications. The current main use of the tunnel being for automotive and train aerodynamics, constrained the design to look for a reversible solution. The approach followed was then to install a grid o...
Abstract The D5 aeroacoustic wind tunnel at Beihang University is a newly commissioned small-scale closed-circuit wind tunnel with low turbulence intensity and low background noise. The wind tunnel is built to study both aerodynamic and aeroacoustic performance of aircraft components or scaled models. The wind tunnel has two types of test sections, the closed type test section is used for aerodynamic tests while the open type test section is mainly used for aeroacoustic experiments. Both types o...
#2Bert Blocken(TU/e: Eindhoven University of Technology)H-Index: 30
Abstract This paper presents a detailed experimental analysis of flow and dispersion by cross-ventilation in five generic isolated single-zone buildings with different opening positions. First, flow visualization is performed illustrating the highly transient flow and dispersion process dominated by a flapping jet with pronounced Kelvin–Helmholtz instabilities. Next, the mean velocity field, the turbulent kinetic energy field, the mean concentration field and the concentration fluctuation field ...
A low-speed wind tunnel has been built and tested in the Laboratory of Fluid Mechanics at the Hochiminh City University of Technology for teaching and doing research. The wind tunnel is an open-jet type with the nozzle area of 1m x 1m and the maximum wind speed of 14 m/s. To evaluate quality of the wind flow created by the tunnel, velocity distribution and turbulence intensity of airflow were measured at the nozzle by a thermal-couple anemometer. The measurements indicated that the turbulence in...
Intercomponent energy transfer (IET) is a direct consequence of the incompressibility-preserving action of pressure. This action of pressure is inherently non-local, and consequently its modelling must address multi-point physics. However, in second moment closures, pragmatism mandates a single-point closure model for the pressure–strain correlation, that is, the source of IET. In this study, we perform a rapid distortion analysis to demonstrate that for a given mean-flow gradient, IET is strong...
Preface Nomenclature 1. Introduction 2. The exact equations 3. Characterization of stress and flux dynamics: elements required for modelling 4. Approaches to closure 5. Modelling the scale-determining equations 6. Modelling in the immediate wall vicinity and at low Ret 7. Simplified schemes 8. Wall functions References Index.
Last. Roger Temam(IU: Indiana University)H-Index: 82
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Preface Acknowledgements 1. Introduction and overview of turbulence 2. Elements of the mathematical theory of the Navier-Stokes equations 3. Finite dimensionality of flows 4. Stationary statistical solutions of the Navier-Stokes equations, time averages and attractors 5. Time-dependent statistical solutions of the Navier-Stokes equations and fully developed turbulence References Index.
This paper presents a reformulated version of the author'sk-ω model of turbulence. Revisions include the addition of just one new closure coefficient and an adjustment to the dependence of eddy viscosity on turbulence properties. The result is a significantly improved model that applies to both boundary layers and free shear flows and that has very little sensitivity to finite freestream boundary conditions on turbulence properties. The improvements to the k-ω model facilitate a significant expa...