AUTOMOTIVE TESTING AND OPTIMIZATION. Tools for designing tomorrow's vehicles

Transcription

1 AUTOMOTIVE TESTING AND OPTIMIZATION Tools for designing tomorrow's vehicles

2 2 Measurement of flow around the side mirror by Particle Image Velocimetry (PIV). Courtesy of Visteon Deutschland GmbH

3 Our advanced measurement solutions, including NDT and strain/stress measurement systems, allow you to reduce development costs and time to market by optimizing vehicle aerodynamics, engine design and thermal comfort. Shortening the Development Process Greater focus on improved fuel economy and emission reductions, along with a growing consumer demand for comfort, safety and performance, have created fierce competition in the automotive industry. In order to gain a competitive edge, manufacturers must find efficient ways to accelerate product development. Dantec Dynamics offers a wide range of solutions for the measurement and optimization of: vehicle aerodynamics, weight and heat management, thermal comfort in the passenger compartment, diagnostics of combustion, as well as Nondestructive Testing and strain/stress measurements of mechanical components. Our products are designed to minimize development time and costs. Supplementing our experimental techniques with simulation tools such as Computational Fluid Dynamics (CFD) and Computer Aided Design (CAD) is an important step towards shortening the development process. This brochure outlines examples of Dantec instrumentation for applications in the automotive industry. 3

4 Improving Vehicle Aerodynamics Reducing Drag Our instrumentation is widely used in automotive wind tunnels for determining and maximizing the aerodynamic efficiency of the underbody, rear end, wheel arches and side mirrors. Laser based diagnostic systems such as Particle Image Velocimetry (PIV) and Laser Doppler Anemometry (LDA) can be placed outside the test section to measure air flow nonintrusively, both in model and in full scale wind tunnels. Rapid flow field measurements can be made with PIV, helping to identify wake vortices and other spatial flow structures. LDA can measure in confined spaces where PIV is difficult to apply. Constant Temperature Anemometry (CTA), using tiny hot-wire probes, is capable of measuring turbulence spectra and boundary layers. Drag reduction by active vortex generators (AVG), measured by PIV. Left: without AVG, right: with AVG. Courtesy of PSA. Flow behind a side mirror. Left: Light sheet Courtesy of Pininfarina. 4

5 LDA measurement of wake flow in a model wind tunnel. Courtesy of Daimler AG. Reducing Noise CTA is well suited for aeroacoustic experiments, studying the turbulence spectra and hence noise generation. Its analog velocity signal can be analyzed by spectrum analyzers, and can be correlated with microphone signals to study the interaction between the sound field and turbulence. The spatial behavior of the flow can be related to the sound field using probe arrays with multichannel CTA systems. LDA is well suited for boundary layer measurements due to its very small measurement volume and the non-intrusive nature of the method. illumination. Right: PIV result, velocity vector field. PIV measurement of the flow along a sun roof. Courtesy of BMW AG. 5

6 Enhancing Engine Performance Improving Fuel Economy and Reducing Emissions Fuel injection and distribution are key processes in energy production and the quantity of pollutants emitted from engines, gas turbines and burners. Understanding and optimizing fuel atomization, vaporization and mixing require advanced measurements to characterize technical alternatives. The need to reduce emissions of CO2, NOX and other pollutants from combustion processes is becoming increasingly important due to their impact on global warming and human health. In order to address these concerns, Dantec Dynamics provides diagnostic solutions to measure soot concentration, particle size, and concentration of unburned hydrocarbons. Methods for increasing the efficiency of exhaust gas after treatment strategies are also addressed. Optimizing Fuel Injection and Mixing The uniformity of droplet distribution in the combustion chamber is influenced by spray geometry parameters including cone angle, position and length. High speed cameras freeze the droplet motion and provide measurements of spray geometry parameters. For fuel injection studies, details on droplet size and velocity are fundamental for maximizing the efficiency and reducing emissions in diesel engines. Phase Doppler Analysis (PDA) is widely used for studying spray atomization. Fuel injector spray geometry by Mie scattering analysis. 6

7 Use of PDA for diesel injection spray analysis in a high-pressure chamber. Courtesy of Achates Power Inc. Fuel Injection Lab, US. Measuring Fuel Spray Temperature The air-fuel ratio is directly influenced by the spray droplet temperature and fuel vapor concentration in the combustion chamber. The new two-color Laser-Induced Fluorescence (LIF) technique can be applied to measure fuel spray temperature and provides data on the correlation between injection conditions and spray temperature for improvement of CFD models. Minimizing Soot in Diesel Engines Soot is a by-product of incomplete combustion and is a major source of pollution in diesel engine exhaust. The Laser- Induced Incandescence (LII) technique allows in-cylinder investigations to reveal both where the soot is formed in the combustion chamber and when this formation occurs in the engine cycle. The operating conditions under which soot formation occurs may also be determined using LII. a b c d Temperature maps of dodecane sprays from a diesel injector at three different chamber temperatures. Courtesy of F. Lemoine. LEMTA, University of Nancy, France. View through an optical piston from below (a and b) and from the side (c and d), together with single-shot soot volume fraction images. Courtesy of H. Bladh, Lund University, Sweden. 7

8 Optimizing Components Materials Testing under Mechanical or Thermal Load Effective development of advanced materials and components requires an understanding of their behavior under load in variable conditions. Optical full-field measurement techniques are increasingly being used in material testing, fracture mechanics and vibration analysis. Dantec Dynamics optical measurement systems are designed for complete three dimensional, full field and highly sensitive displacement and strain analysis. Digital Image Correlation measurements are non-contact and can be performed on the entire measurement area of nearly any material or component. The Digital Image Correlation system can be used for tensile, torsion, bending and combined loading tests on a wide range of materials. The use of high speed sensors enables the analysis of highly dynamic events. Optical strain and vibration measurement systems can significantly reduce the inspection time for complex components such as gearboxes, engines, car bodies and exhaust pipes. Full field strain analysis at a critical position on a front axle with fatigue problems. Courtesy of Renault, France. Vibration analysis at exhaust pipes. 8

9 Q-400 digital image correlation system for real time 3D displacement and strain measurement. Advantages over conventional measurement equipment such as strain gauges include a significantly reduced surface preparation time, along with providing greater detailed information about local deformations and strains. Flow through Cooling Module - Optimized System Performance The characterization of airflow through the cooling module is critical for optimizing performance of air conditioning and engine cooling circuits as well as vehicle aerodynamics. LDA is useful for measuring the airflow and recirculation through, as well as the velocity distribution in front of and around the cooling module. The optimization of airflow through the module creates greater efficiency and also provides downsizing potential for certain components. Strain measurement at single cogs of gearwheels. LDA measurement between radiator and condenser. Left: Experimental setup. Right: Velocity profile plot. 9

10 Improving Passenger Comfort Measurement of thermal comfort by thermal manikin equipped with draft probes. The improvement of climatic comfort and safety within passenger vehicles requires a clear understanding of airflow behavior. PIV is used in the study and analysis of fluid flow measurements in the passenger cabin and around instrument panel registers. Characterization of airflow over the windscreen and side windows is crucial to understanding and optimizing de-icing performance. Flow visualization enables the visual representation of airflow. The use of LDA in the lab can minimize time intensive deicing tests in the climate chamber, thus reducing overall development costs. Our ComfortSense system, dedicated to multi-point measurements of thermal comfort, includes omnidirectional draft probes as well as temperature, humidity and operative temperature probes. Draft probes designed for integration in thermal manikins are also available : Flow visualization by laser light sheet of the airflow at the wind screen. Courtesy of Visteon Deutschland GmbH. 2: Hot-wire measurement of airflow out of instrument panel register. 3: Flow pattern on windscreen measured by LDA. Courtesy of Visteon Deutschland GmbH. 10

11 11

12 About Dantec Dynamics Dantec Dynamics is the leading provider of laser optical measurement systems and sensors for fluid flow characterization and materials testing. Since 1947 we have provided solutions for customers to optimize their product and component testing. Dantec Dynamics provides quality solutions for an extensive list of customers in the areas of: Fluid Mechanics Thermal Comfort Strain, Stress & Vibration Particle Characterization Microfluidics Non-destructive Testing Combustion Diagnostics Process Control Disatac Tachometers Worldwide representation From our six offices and more than 30 distributors worldwide we approach our customers individually. We examine the specific needs and find the best solution for you. For us you are a long-term partner in improving efficiency, safety and quality of life. A list of representatives is available at our website. DENMARK (headquarters) Dantec Dynamics A/S info@dantecdynamics.com FRANCE Dantec Dynamics S.A.S. france@dantecdynamics.com UNITED KINGDOM Dantec Dynamics Ltd. uk@dantecdynamics.com USA Dantec Dynamics Inc. usa@dantecdynamics.com GERMANY Dantec Dynamics GmbH germany@dantecdynamics.com JAPAN Dantec Dynamics K.K. japan@dantecdynamics.com The specifications in this document are subject to change without notice. Dantec Dynamics is trademark of Dantec Dynamics A/S. Publication No.: 291_v1