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Introduction
Published in Krishnan Murugesan, Modeling and Simulation in Thermal and Fluids Engineering, 2023
A wind tunnel is a facility in which these scaled physical models can be tested by allowing air to flow over the structures at different flow conditions depicting the actual working environments. Figure 1.2 demonstrates the wind tunnel testing of an aircraft model and other testing models for bridges and chimneys.
Wind Tunnels
Published in Ethirajan Rathakrishnan, Instrumentation, Measurements, and Experiments in Fluids, 2020
In aerospace applications, wind tunnels are used to test models of aircraft and engine components. During a test, the model is placed in the test-section of the tunnel and air, at desired Mach numbers, is made to flow past the model, to measure the pressure distribution over the model and the aerodynamic forces, such as lift, drag, and side force, acting on the model, and moments, such as rolling, pitching, and yawing moments. The instrument used for measuring the pressure distribution is a manometer or pressure transducer. For measuring the forces and moments, usually wind tunnel balance is used. We must measure six components, three forces (lift, drag, and side force) and three moments (pitching, rolling, and yawing moments), to completely describe the conditions on the model when subjected to the flight condition.
Rail Vehicle Aerodynamics
Published in Simon Iwnicki, Maksym Spiryagin, Colin Cole, Tim McSweeney, Handbook of Railway Vehicle Dynamics, 2019
A wind tunnel is a specially designed tunnel that can generate manually controllable air flow by using a powerful fan system or other means. Based on the theory of relative motion and similarity principles, a wind tunnel can be used to conduct aerodynamic tests for rail vehicles.
Ship staff wind comfort and wind safety in the walkways of containerships and case study for a feeder containership
Published in Ships and Offshore Structures, 2022
Hasan Islam Copuroglu, Emre Pesman
The objective of the present paper is to investigate the ship staff’s wind comfort and wind safety on deck with an example case for a feeder containership. The studies are carried out with numerical methods (Computational Fluid Dynamics). Wind velocities for different measuring points in the walkways are calculated and the effect of those wind velocities is discussed. In the literature, the number of articles that about wind safety and comfort for ship staff is very few and most of them about general safety procedures. So there is no article with specific subject which is wind safety and comfort for ship staff. So the aim of this study is to create a starting point for the work to be done for the wind comfort and safety of the ship staff. The outline of the paper is as follows. First, basics and usefulness of the method used is provided in Section 2.1. Next, the validation study is described in Section 2.2. The wind tunnel measurement setup and the Computational fluid dynamics (CFD) simulations are defined in Section 2.3. In Section 3, comparative CFD results of the cases are given. The Graphical representations of these cases for walkways are also shown in this section. Finally, Section 4 contains discussion, future work, and conclusions.
Aspiration ratio of a double-shrouded probe under low pressure conditions in troposphere
Published in Aerosol Science and Technology, 2020
Jun-Hyung Lim, Su-Hoon Park, Se-Jin Yook, Kang-Ho Ahn
The wind tunnel was fabricated as shown in Figure 3, to measure the aspiration ratio of a double-shrouded probe under low pressure and high airflow velocity conditions. The wind tunnel is composed of two inlets, two outlets, one entrance region, and one test section. A Pitot tube was used to measure pressure and airflow velocity in the test section. The Pitot tube was designed to determine the uniformity of the air velocity in the test section by installing it in the radial direction of the wind tunnel. The particle number concentration in free-stream (C∞) was measured using an isokinetic sampling probe shown in Figure 1a. The particle number concentration (Ci) of the sampled aerosol was measured using a double-shrouded probe shown in Figure 1c. The aspiration ratio of the double-shrouded probe was calculated using Equation (1) with the above measurement results.
Optimal design of sand blown wind tunnel
Published in Automatika, 2020
Bin Yang, Yong Su, Xiaosi Zhou, Bo Tang, Yang Zhang, Yinghui Ren
The designed environmental wind tunnel must meet the following three requirements to realize the simulations of continuous migration of aeolian sand and sandstorm process: (1) the airflow velocity in the wind tunnel should be sufficiently strong; (2) the power fan inertia should be as small as possible to facilitate variable speed adjustment and ensure high flow rate; and (3) the airflow field in the wind tunnel should have high turbulence intensity to reproduce the near-surface strong turbulence atmosphere. The numerical simulation of the entire structure and corresponding flow fields of the wind tunnel is an undeniably advanced and effective technique for the optimization of wind tunnel design [43]. This work focuses on 3D computational fluid dynamics (CFD) of the wind tunnel technology. The optimal power system configuration is determined through comparative simulation and analysis of the boundary layer flow characteristics in the wind tunnel, such as airflow velocity, turbulence intensity, and boundary layer thickness, under different power system configurations (single/dual fans). The present study aims to provide simulation data references for the wind tunnel upgrading and related experiments in wind blowing sand transport.