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Viewing 1 to 30 of 3472
2017-06-05
Technical Paper
2017-01-1783
Chris Todter, Olivier Robin, Paul Bremner, Christophe Marchetto, Alain Berry
Abstract Surface pressure measurements using microphone arrays are still challenging, especially in an automotive context with cruising speeds around Mach 0.1. The separated turbulent boundary layer excitation and the side mirror wake flow generate both acoustic and aerodynamic components, which have wavenumbers that differ by a factor of approximately 10. This calls for high spatial resolution measurements to fully resolve the wavenumber-frequency spectrum. In a previous publication [1], the authors reported a micro-electro-mechanical (MEMS) surface microphone array that successfully used wavenumber analysis to quantify acoustic versus turbulence loading. It was shown that the measured surface pressure at each microphone could be strongly influenced by self-noise induced by the microphone “packaging”, which can be attenuated with a suitable windscreen.
2017-06-05
Journal Article
2017-01-1825
Takenori Miyamoto, Hiroshi Yokoyama, Akiyoshi Iida
Abstract Intense aeroacoustic feedback noises may radiate from flow around an airfoil, rearview mirror with small gaps and so on. Reductions of these noises are important issues in the development of industrial application. The intense noise from a bonnet of the automobile is one of the typical problems of acoustic feedback noise. In order to reduce this noise, plasma actuator (PA) was utilized to control flow and acoustic fields. The aim of this investigation is to clarify the effects of flow control by the PA on noise reduction and the noise reduction mechanism. Wind tunnel experiments were conducted with a half scale bonnet model and a low noise wind tunnel. Simultaneous measurements of flow and noise fields were conducted to understand the generation mechanism of the bonnet noise. Coherent output power (COP) of the velocity fluctuations with reference to far-field sound pressure was measured to visualize noise source distribution.
2017-06-05
Journal Article
2017-01-1786
Hiroshi Yokoyama, Ryo Adachi, Taiki Minato, Akiyoshi Iida
Abstract The objective of this paper is to clarify the mechanism for the reduction of cavity tone with blowing jets aligned in the spanwise direction in the upstream boundary layer. Also, the effects of spacing of the jets on the reduction are focused. To achieve these objectives, direct aeroacoustic simulations were conducted along with wind tunnel experiments. The depth-to-length ratio of cavity was D/L = 0.5. The incoming boundary layer was laminar, where the boundary layer thickness was δ/L = 0.055. The predicted flow fields without control show that two-dimensional large-scale vortices are shed and become acoustic sources in the cavity. The effects of spanwise spacing of spanwise-aligned jets on the cavity flow and tone were clarified with computations and experiments with the different pitches of s/L = 0.1 - 1.0 (s/δ = 1.8-18.2). As a result, the largest reduction level was obtained for s/L = 0.5.
CURRENT
2017-05-08
Standard
AIR6211A
This test method provides stakeholders (runway deicing chemical manufacturers, users, regulators, and airport authorities) with a relative ice penetration capacity of runway deicing/anti-icing chemicals, by measuring the ice penetration as a function of time. Such runway deicing/anti-icing chemicals are often also used on taxiways and other paved areas. This test method does not quantitatively measure the theoretical or extended time of ice penetration capability of ready-to-use runway deicing/anti-icing chemicals in liquid or solid form.
2017-05-03
WIP Standard
ARD6954
This SAE Aerospace Resource Document (ARD) document covers the requirements for a self-propelled GRV, intended for use at airports to collect spent aircraft de-icing fluid (ADF) from the surface of de-icing areas. This unit will recover de-icing fluid from the surface, which will be stored in a containment unit on the vehicle. The GRV must be capable of night and day operations in all weather conditions, as required.
2017-04-30
Book
Eduardo Galindo, David Blanco, Chris J. Brace, Edward Chappell, Richard Burke
The use of the chassis dynamometer test cells has been an integral part of the vehicle development and validation process for several decades, involving specialists from different fields, not all of them necessarily experts in automotive engineering. CHASSIS DYNAMOMETER TESTING: Addressing the Challenges of New Global Legislation (WLTP and RDE) sets out to gather knowledge from multiple groups of specialists to better understand the testing challenges associated with the vehicle chassis dynamometer test cells, and enable informed design and use of these facilities.
2017-04-27
Magazine
Interoperability Standards Pave the Way for Modular Robotic Manipulators Solar Powering UAVs Deploying COTS Subsystems in UUVs Developing a Multi-Modal UGV Robot Control Interface Fast-Tracking Autonomous Vehicles with Simulation Gesture-Based Controls for Robots: Overview and Implications for Use by Soldiers Identifying the Flow Physics and Modeling Transient Forces on Two-Dimensional Wings Experimental Confirmation of an Aquatic Swimming Motion Theoretically of Very Low Drag and High Efficiency The Scaling of Loss Pathways and Heat Transfer in Small Scale Internal Combustion Engines A Guide for Developing Human-Robot Interaction Experiments in the Robotic Interactive Visualization and Experimentation Technology (RIVET) Simulation
CURRENT
2017-04-18
Standard
J2966_201704
This document outlines general requirements for the use of CFD methods for aerodynamic simulation of medium and heavy commercial ground vehicles weighing more than 10 000lbs. The document provides guidance for aerodynamic simulation with CFD methods to support current vehicle characterization, vehicle development, vehicle concept development and vehicle component development. The guidelines presented in the document are related to Navier-Stokes and Lattice-Boltzmann based solvers. This document is only valid for the classes of CFD methods and applications mentioned. Other classes of methods and applications may or may not be appropriate to simulate the aerodynamics of medium and heavy commercial ground vehicle weighing more than 10 000lbs.
2017-04-11
Journal Article
2017-01-9450
Ali Reza Taherkhani, Carl Gilkeson PhD, Philip Gaskell PhD, Rob Hewson PhD, Vassili Toropov PhD, Amin Rezaienia PhD, Harvey Thompson
Abstract This paper investigates the optimization of the aerodynamic design of a police car, BMW 5-series which is popular police force across the UK. A Bezier curve fitting approach is proposed as a tool to improve the existing design of the warning light cluster in order to reduce drag. A formal optimization technique based on Computational Fluid Dynamics (CFD) and moving least squares (MLS) is used to determine the control points for the approximated curve to cover the light-bar and streamline the shape of the roof. The results clearly show that improving the aerodynamic design of the roofs will offer an important opportunity for reducing the fuel consumption and emissions for police vehicles. The optimized police car has 30% less drag than the non-optimized counter-part.
2017-04-07
WIP Standard
J1252
The scope of this SAE Recommended Practice is sufficiently broad that it encompasses the full range of full-scale medium and heavy duty vehicles represented as either full-scale or reduced-scale wind tunnel models. The document provides guidance for wind tunnel testing to support current vehicle characterization, vehicle development, vehicle concept development, and vehicle component development.
2017-04-06
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-06
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-05
Event
The complexity and pace of product development has followed the advancements in science and technology, customer demands, and increased market competition in recent years. Product reliability, which is seen as a measure of quality over time, is becoming a critical discriminating factor from the customer standpoint. It dictates that the system will deliver failure-free performance of all required functions for a specified time under a set of stated conditions. Reliability tools and methods are increasingly used to build in and grow reliability throughout the design process. Modern product design and development involve a disciplined process with milestones and key design maturity deliverables. The process starts with translating the requirements gathered from the Voice of the Customer (VOC), government regulations, and corporate standards into engineering specifications. Design concepts are selected and narrowed down to the final design based on the collected data.
2017-04-05
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
Viewing 1 to 30 of 3472

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