Two-point Aerodynamic Model Identification from Dynamic Wind Tunnel Tests

2016 ◽  
Author(s):  
Joaquim N. Dias ◽  
Roberto D. Girardi
Keyword(s):  
Wind Tunnel ◽  
Model Identification ◽  
Wind Tunnel Tests ◽  
Aerodynamic Model

Optimisation of a Sailing Rig using Wind Tunnel Data

1997 ◽  
Author(s):  
IMC Campbell
Keyword(s):  
United States ◽  
Wind Tunnel ◽  
Research Programme ◽  
The United States ◽  
Wind Tunnel Tests ◽  
Aerodynamic Model ◽  
Analysis Methods ◽  
Wind Tunnel Data ◽  
Made In

A number of wind tunnel tests have been conducted by the Wolfson Unit in aid of the development of sailing rigs for both cruising and racing boats, including recent tests for the United States Sailing Association as part of the joint IMS/PHRF research programme. In the process of these tests developments have been made in both the test techniques and the analysis methods, which have enabled the components of drag to be identified for different sail settings. This paper describes the tests for evaluating the upwind rig performance of a sloop and compares the components of drag with those in the aerodynamic model used in the IMS VPP. The aerodynamic behaviour of the rig is described using plots of the variation of sail forces and moments with sail settings with the aim of helping sailors understand the effects of changing sail settings. It is shown that the wind tunnel data match closely the IMS aerodynamic model and that this model can be simply programmed by sailors and designers into a spreadsheet to enable the rig planform to be optimised for particular conditions. The results are compared with those obtained using a full VPP calculation.

An investigation of lateral-directional departure behavior based on yawing–rolling coupled wind tunnel tests

2017 ◽  
Vol 232 (16) ◽  
pp. 2989-3000
Author(s):  
Lin Shen ◽  
Da Huang ◽  
Genxing Wu
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Characteristics ◽  
Flight Simulation ◽  
Wind Tunnel Tests ◽  
Unsteady Aerodynamic ◽  
Model Based ◽  
Aerodynamic Model ◽  
Data Prediction ◽  
Text Model ◽  
Departure Behavior

The traditional aerodynamic model based on the dynamic derivative tests and the [Formula: see text] model based on the yawing–rolling coupled motion tests are compared with respect to aerodynamic data, prediction of lateral-directional departure, and flight simulation. The study shows that the traditional model cannot fully reveal the unsteady aerodynamic characteristics and predict completely the departure behavior due to yaw–roll coupling. On the other hand, the [Formula: see text] model can reveal the departure behavior of an aircraft at some specific coupling ratios when the angle of attack reaches a critical value or more, using the aerodynamic data obtained from the yawing–rolling coupled wind tunnel tests. The comparison of flight simulation results shows that the lateral-directional departure is closely related to the coupling ratios, and for the investigated aircraft, the departure is mainly caused by the unsteady yawing and rolling moments at the coupling ratios showing unstable features.

A predictive critical flutter wind speed modeling for long-span bridges

2020 ◽  
Vol 23 (9) ◽  
pp. 1823-1837
Author(s):  
Kun Lin ◽  
Minghai Wei ◽  
Hongjun Liu ◽  
Huafeng Wang
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Wind Speeds ◽  
Long Span ◽  
Aerodynamic Model ◽  
Proposed Model

In this article, a two-dimensional Lighthill aerodynamic model is first extended to three-dimensional space, and then combined with the larger Von Karman plate deformation theory, a model for predicting the critical flutter wind speeds of long-span bridges in the primary design is proposed. The predictions of the presented model are compared to the results of wind tunnel tests for five long-span bridges with different main girder section forms. After that, based on the proposed model, the effects of width to span ratio and thickness to span ratio on the critical flutter wind speeds of long-span bridges are investigated. The results show that the differences between the proposed model and wind tunnel tests are only 7%–14%. Therefore, the presented model can assess the flutter wind speed in preliminary design stages of a bridge. The results also reveal that width to span ratios between 1/30 and 1/10 and thickness to span ratios between 1/300 and 1/100 are optimal for long-span bridges.

scholarly journals Wind-Induced Phenomena in Long-Span Cable-Supported Bridges: A Comparative Review of Wind Tunnel Tests and Computational Fluid Dynamics Modelling

2021 ◽  
Vol 11 (4) ◽  
pp. 1642
Author(s):  
Yuxiang Zhang ◽  
Philip Cardiff ◽  
Jennifer Keenahan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Careful Analysis ◽  
Wind Effects ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Long Span ◽  
Comparative Review ◽  
Dynamics Modelling

Engineers, architects, planners and designers must carefully consider the effects of wind in their work. Due to their slender and flexible nature, long-span bridges can often experience vibrations due to the wind, and so the careful analysis of wind effects is paramount. Traditionally, wind tunnel tests have been the preferred method of conducting bridge wind analysis. In recent times, owing to improved computational power, computational fluid dynamics simulations are coming to the fore as viable means of analysing wind effects on bridges. The focus of this paper is on long-span cable-supported bridges. Wind issues in long-span cable-supported bridges can include flutter, vortex-induced vibrations and rain–wind-induced vibrations. This paper presents a state-of-the-art review of research on the use of wind tunnel tests and computational fluid dynamics modelling of these wind issues on long-span bridges.

Galloping vibration of stay cable installed with a rectangular lamp: Field observations and wind tunnel tests

2021 ◽  
Vol 215 ◽  
pp. 104685
Author(s):  
An Miao ◽  
Li Shouying ◽  
Liu Zhiwen ◽  
Yan Banfu ◽  
Li Longan ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Field Observations ◽  
Stay Cable ◽  
Wind Tunnel Tests

Wind tunnel tests and dynamic analysis of wind-induced response of a transmission tower on a hill

2021 ◽  
pp. 136943322110339
Author(s):  
Jian Guo ◽  
Changliang Xiao ◽  
Jiantao Li
Keyword(s):  
Wind Tunnel ◽  
Wind Field ◽  
Dynamic Responses ◽  
Interactive Effects ◽  
Induced Response ◽  
Transmission Tower ◽  
Structural Dynamic ◽  
Wind Tunnel Tests ◽  
Hill Slope ◽  
The Hill

A hill with a lattice transmission tower presents complex wind field characteristics. The commonly used computational fluid dynamics (CFD) simulations are difficult to analyze the wind resistance and dynamic responses of the transmission tower due to structural complexity. In this study, wind tunnel tests and numerical simulations are conducted to analyze the wind field of the hill and the dynamic responses of the transmission tower built on it. The hill models with different slopes are investigated by wind tunnel tests to measure the wind field characteristics, such as mean speed and turbulence intensity. The study shows that the existence of a transmission tower reduces the wind speed on the leeward slope significantly but has little effect on the windward slope. To study the dynamic behavior of the transmission tower, a hybrid analysis procedure is used by introducing the measured experimental wind information to the finite element tower model established using ANSYS. The effects of hill slope on the maximum displacement response of the tower are studied. The results show that the maximum value of the response is the largest when the hill slope is 25° compared to those when hill slope is 15° and 35°. The results extend the knowledge concerning wind tunnel tests on hills of different terrain and provide a comprehensive understanding of the interactive effects between the hill and existing transmission tower regarding to the wind field characteristics and structural dynamic responses.

Sign in / Sign up

Export Citation Format

Share Document