Wind-Tunnel Based Definition of the AFE Aerothermodynamic Environment

1992 ◽  
pp. 109-181
Author(s):  
Charles G. Miller ◽  
W. L. Wells
Keyword(s):  
Wind Tunnel ◽  
Definition Of

CFD for Engine-Airframe Integration

1987 ◽  
Vol 109 (2) ◽  
pp. 132-141
Author(s):  
G. C. Paynter ◽  
C. K. Forester ◽  
E. Tjonneland
Keyword(s):  
Wind Tunnel ◽  
Research And Development ◽  
Mesh Generation ◽  
Experimental Validation ◽  
Turbulence Modeling ◽  
Numerical Error ◽  
Current Status ◽  
Error Assessment ◽  
Definition Of ◽  
And Control

This article provides an assessment of current CFD technology with application to propulsion integration, a definition of research and development needed to extend the technology, and a discussion of numerical error assessment and control. The CFD technology is divided into the elemental areas of the computer system, algorithms, geometry and mesh generation, turbulence modeling, and experimental validation; the current status and major issues in each of these areas are defined. Sources of numerical error are identified and some strategies for determining and controlling these are presented. CFD will have an impact on propulsion integration equivalent to that of the wind tunnel as CFD technology matures. This maturation will lead to a system which integrates the elemental areas of CFD for applications.

Définition d'un site réel répondant aux conditions d'une simulation d'une couche superficielle de l'atmosphère

1990 ◽  
Vol 17 (4) ◽  
pp. 543-546
Author(s):  
P. R. Louchez ◽  
J. Druez
Keyword(s):  
Surface Layer ◽  
Wind Tunnel ◽  
Atmospheric Turbulence ◽  
Stationary State ◽  
Wind Pressure ◽  
Neutral Surface ◽  
Design Problems ◽  
Neutral Surface Layer ◽  
Definition Of

Given the difficulty of numerically modelling atmospheric turbulence, laboratory wind-tunnel simulations have been used to solve a variety of design problems involving pollution, wind pressure on structures, etc. Most often, a dry, homogeneous, stationary, barotropic, and neutral surface layer is assumed for the simulation. However, such an assumption severely limits the applicability of the findings. This paper presents a definition of a real site for solving the types of design problems mentioned. A simple numeric application is performed on a simulation of wind drag on a vehicle travelling in the countryside under particular stationary-state and thermic-neutrality conditions. [Journal translation]

A Dimensionless Representation of the Turbulence Driven Panel Response

2010 ◽  
Author(s):  
E. Ciappi ◽  
F. Magionesi ◽  
S. De Rosa ◽  
F. Franco
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Excitation Frequency ◽  
Structural Response ◽  
Data Sets ◽  
Towing Tank ◽  
Functional Relations ◽  
Plane Plate ◽  
Definition Of ◽  
Tank Water

In this paper a summary is presented concerning several experiences in predicting and measuring the structural response under turbulent boundary layer excitations. The theoretical, numerical and experimental evaluations involved both wind tunnel and towing tank (water) tests in which a flow wetted a plane plate over one face. A critical review of all these sets is presented together with the possibility to adopt a dimensionless representation for the response. This is done in order to tentatively compare measurement sets and/or predictive results obtained in nominally different conditions. Specifically, the attention is devoted to the definition of the possible normalisation of the required axes: the excitation frequency and the response metric. To this aim relations suggested by the dimensional analysis are applied to four distinct data sets finding the best choice of dimensionless parameters that allow the collapse of the different curves in a single one. The functional relations between these parameters are discussed and an analytical expression for the dimensionless plate response is obtained.

scholarly journals An Approach to the Definition of the Aerodynamic Comfort of Motorcycle Helmets

Vehicles ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 545-556
Author(s):  
Lorenzo Scappaticci ◽  
Giacomo Risitano ◽  
Dario Santonocito ◽  
Danilo D’Andrea ◽  
Dario Milone
Keyword(s):  
Neural Network ◽  
Wind Tunnel ◽  
Convolutional Neural Network ◽  
Aerodynamic Characteristics ◽  
Wind Tunnel Testing ◽  
Neck Stiffness ◽  
Definition Of ◽  
Motorcycle Helmets ◽  
Reliable Testing

The aim of this work is to obtain a reliable testing methodology for the characterization of the perceived aerodynamic comfort of motorcycle helmets. Attention was paid to the rider’s perception of annoying vibrations induced by wind. In this optic, an experimental comparative campaign was performed in the wind tunnel, testing 16 helmets in two different configurations of neck stiffness. The dataset was collected within a convolutional neural network (CNN or ConvNet) of images, creating a ranking by identifying the best and the worst helmets. The results revealed that each helmet has unique aerodynamic characteristics. Depending on the ranking scale previously created, the aerodynamic comfort of each helmets can be classified within the scale.

Open Rotor Design Strategy: From Wind Tunnel Tests to Full Scale Multi-Disciplinary Design

2015 ◽  
Author(s):  
Jonathan Vlastuin ◽  
Clément Dejeu ◽  
Anthony Louet ◽  
Jérôme Talbotec ◽  
Ingrid Lepot ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Design Methodology ◽  
Wind Tunnel Test ◽  
Design Strategy ◽  
Design Guidelines ◽  
Full Scale ◽  
Wind Tunnel Tests ◽  
Open Rotor ◽  
Definition Of

For several years, Safran has been involved in the design and optimization of contra rotating open rotors. This innovative architecture is known for allowing drastic reduction in fuel burn, but its development is facing complex technological challenges such as acoustics, aerodynamics, and weight penalty due to the mechanical complexity of an Open Rotor. Since 2010, Safran has been developing the experimental test bench HERA (1/5 mock-up scale) to improve the understanding of the complex aerodynamics and acoustics phenomena involved in the counter rotating propellers configuration. Isolated and installed low speed and high speed wind tunnel campaigns, including PIV measurements have been extremely helpful in defining design guidelines for full scale open rotor specification. These tests have been used as CFD feed-back among other purposes. An iterative process involving CFD optimization (in close collaboration with Cenaero) and wind tunnel test campaigns has been developed over the last 4 years and has led to the definition of an innovative design strategy, which has been successfully tested during the process of the full scale counter rotating propellers design for the SAGE2 ground test demonstrator engine. This phase has evidenced the absolute necessity of a multi-disciplinary design method when it comes to full scale and “rig-ready” design. Ensuring high propulsive efficiency and at the same time, minimizing the acoustic level, while maintaining severe mechanical constraints such as weight, inertia and proper dynamic positioning under control, requires a dedicated and integrated “all inclusive” design process. The aim of this paper is to present the design methodology and some of the wind tunnel tests results carried out over the last 4 years, which have led to the definition of a novel multidisciplinary design methodology that involves CFD, FEM and acoustics.

Modeling and Design of an Experimental Demonstrator of Blade Twist Through the SMA Technology

2019 ◽  
Author(s):  
Salvatore Ameduri ◽  
Antonio Concilio ◽  
Bernardino Galasso
Keyword(s):  
Structural Analysis ◽  
Wind Tunnel ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Design Approach ◽  
Wind Tunnel Tests ◽  
Definition Of ◽  
Operational Envelope ◽  
Rotary Wing

Abstract The paper at hand focuses on the modeling and design of an experimental demonstrator of a blade segment, twisted through Shape Memory Alloy technology. The demonstrator will be used for the wind tunnel tests planned within the Project of SABRE (H2020 Eu Program), aimed at investigating the effects produced by blade oriented morphing technologies, both in fixed and rotary wing configurations. The design approach adopted for a SMA twist concept is herein described in its different phases, moving from the definition of the preliminary layout, its fitting to the reference blade mechanical features, the preliminary structural analysis to confine its operational envelope, up to the simulation of the SMA actuation through a SMA torque element. The results are presented in terms of operational envelope limits and transmitted twist.

The accuracy of internal wind tunnel balances for wind tunnel force measurements, the problem of definition and verification

2001 ◽  
Vol 105 (1050) ◽  
pp. 443-449
Author(s):  
B. Ewald
Keyword(s):  
Wind Tunnel ◽  
Strain Gauge ◽  
Internal Strain ◽  
Absolute Accuracy ◽  
Force Measurements ◽  
Wind Tunnel Tests ◽  
Physical Sense ◽  
Definition Of ◽  
Accuracy And Repeatability

Abstract For the definition of the acccuracy of an internal strain gauge balance no general agreement exists. So it is difficult or even impossible, to compare balances from different manufacturers or balances used at different places. Since most wind tunnel tests at least in the aeronautical field are done on a reference basis i.e. the results are compared with earlier results achieved with a more or less different configuration, repeatability is at least as important as absolute accuracy or even more important. So also repeatability, which in a physical sense is quite different from accuracy, must be defined and proven for each balance. With the examples of several balances manufactured for the DNW (Deutsch-Niederländischer Windkanal) and ETW (European transonic tunnel) accuracy and repeatability definitions are discussed. A proposal for a generally binding definition of accuracy and repeatability is given.

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