Andre Kaufmann

• Dr.
• Professor at Ravensburg Weingarten University

Knowledge of thermophysical properties of materials is important in the design process to meet the ambitious targets with respect to reliability and performance of many modern machinery. In this paper a simple method for the measurements of thermophysical material properties is presented. A bar of the sample material is heated at one end by a const...

div class="section abstract"> Cooling is a critical factor for improving power density in electrical appliances, especially in integrated drives for mobile applications. However, the issue of distributed losses in electric machines can lead to hotspots and temperature gradients within the electric drive. Traditional cooling jackets use unidirection...

div class="section abstract"> The power density of electric machines is a critical factor in various applications, i.e. like the power train. A major factor to improve the power density is boosting the electric current density, which increases the losses in the limited volume of the electric machine. This results in a need for an optimized thermal...

The book adresses the working mechanism of the Ranque Hilsch Vortex Tube. Starting with thermodynamic analysis and flow structure it gives some arguments for the working principles based on enthalpy balance.

Since battery electric vehicle (BEV) sales are increasing, the calculation of necessary electric power supply, and energy consumption data, and vehicle range is important. The Worldwide harmonized Light vehicles Test Procedure (WLTP) currently in use can deliver data to collect comparable energy consumption data for different vehicles on defined ch...

Due to increasing sales figures, the energy consumption of battery-electric vehicles is moving further into focus. In addition to efficient driving, it is also important that the energy losses during AC charging are as low as possible for a sustainable operation. In many situations it is not possible or necessary to charge the vehicle with the maxi...

The vortex tube can separate a mass flow into a hot and cold mass flow. In this paper, the energy balance in the boundary layer of the vortex tube is analyzed with respect to a possible effect of temperature separation in the boundary layer by the viscous term of the enthalpy balance equation. A Large Eddy Simulation is used to generate the velocit...

Ergänzend zu bestehenden Mobilitätskonzepten entwickeln sich derzeit neue Mikromobilitätskonzepte, die eine Beförderung von Lasten ermöglichen. Hier bieten elektrisch unterstützte Anhänger eine Option, in kommerzieller und privater Nutzung, Waren oder Lasten zu transportieren. Bereits verfügbare elektrisch unterstützte Anhänger benötigen eine Steue...

Dieses Lehrbuch vermittelt die zum Verständnis realer thermischer Prozesse erforderlichen Kenntnisse mit ausführlichen Texten, vielen aussagekräftigen Abbildungen und durchgerechneten Beispielen. Besonderer Wert wird auf die Fachsprache gelegt. Zahlreiche Fragen und Übungen mit Lösungen unterstützen das Selbststudium. Das ausführliche Sachwortverze...

Current and future legal requirements for internal combustion engines (ICE) are increasing the complexity of modern charging systems. Test system manufacturers are facing high demands in terms of hardware specifications and methods for turbocharger testing on a hot-gas test bench. Innovative test systems and methodologies help to improve the qualit...

When it comes to evaluating the thermodynamic and fluid dynamic behavior of a turbocharger (TC) and ensuring the best possible matching to the internal combustion engine, a precise measurement of the characteristic maps is required. Measured on a hot-gas test bench under steady-state conditions, the maps of the compressor and turbine give detailed...

Dieses Lehrbuch vermittelt die zum Verständnis realer thermischer Prozesse erforderlichen Kenntnisse mit ausführlichen verständlichen Texten, vielen aussagekräftigen Abbildungen und durchgerechneten Beispielen. Besonderer Wert wird auf die Fachsprache gelegt. Zahlreiche Fragen und Übungen mit Lösungen unterstützen den Lernerfolg. Das ausführliche S...

Dimensionsanalytische Betrachtungen zum CO2-Ausstoß moderner PKW

A turbocharger has a rotor housing. Said rotor housing has an insertion element. Said insertion element is configured such that the same forms an over-hanging spiral together with said rotor housing.

This article is focused on the quality criteria of the measurement results from Turbo Charger Test Benches. The aim is to define clearly and precisely the quality criteria for the repeatability and reproducibility of the measurement results of turbo charger test benches, in order to give reliable measurement results for later use in engine process...

Characterisation of turbocharger performance is important in gas exchange simulation and engine control unit calibration. Compressor and turbine performance maps are measured on a hot-gas test bed. As a result their performance maps have a large dependence on heat transfer. Gas exchange simulation software assumes adiabatic compressor and turbine m...

A radial compressor, in particular for a turbo-charger, has a spiral housing and a diffuser. The diffuser is constructed such that a low-pressure region in the area of the transition between the spiral housing and the tongue is at least reduced.

The turbocharger having a device for detecting a malfunction of the turbocharger, particularly a malfunction of at least one bearing of the turbocharger has the following features: The device for detecting a malfunction of the turbocharger has a memory device, in which the target operating states of an intact turbocharger are stored. The device for...

Continental and the University of Applied Sciences Ravensburg-Weingarten have developed a new method which measures turbocharger characteristics under engine-relevant operating conditions. This method for extending turbocharger maps determined by steady-state measurement is based on creating turbine expansion ratios and unsteady mass flows similar...

Discrete particle simulation is a well‐established tool for the simulation of particles and droplets suspended in turbulent flows of academic and industrial applications. The study of some properties such as the preferential concentration of inertial particles in regions of high shear and low vorticity requires the computation of autocorrelation fu...

The purpose of this paper is to evaluate the accuracy of the mesoscopic approach proposed by Février et al. [P. Février, O. Simonin, K.D. Squires, Partitioning of particle velocities in gas–solid turbulent flows into a continuous field and a spatially uncorrelated random distribution: theoretical formalism and numerical study, J. Fluid Mech. 533 (2...

The paper addresses the characterization of global burn rates for gasoline fueled internal combustion engines applying direct injection and mixture stratification. Effects of variations in engine speed and load as well as combustion mode (early vs. late fuel injection and mixture stratification) on the global burn rate are discussed. A simple model...

A DNS approach for Eulerian-Eulerian dispersed two-phase flow is discussed. The need for a stress term in the momentum transport equation of the dispersed phase is identified and a simple model for this stress term is proposed. Measurements of the of the dispersed phase quantities such as number density, mesoscopic velocity and stress tensor compon...

Commonly used Lagrangian particle tracking techniques are a well established tool for the computation of particle laden flows. When the numbers of tracked particles is large the approach is known to be numerically too expensive for practical applications. Statistical approaches using a Reynolds averaged type approach show encouraging results with a...

De nombreuses applications industrielles mettent en jeu des écoulements gaz-particules. On peut citer, entre autres, les turbines aéronautiques et les réacteurs à lit fluidisé de l’industrie chimique. Dès lors, l’amélioration de ces dispositifs, imposée par les nouvelles normes européennes sur les émissions polluantes, nécessite une connaissance pr...

A three dimensional unsteady Eulerian-Eulerian approach is proposed to simulate dispersed two-phase flows. In this approach the dispersed phase is treated as the continuous gas phase, through an averaging operator that leads to a system of conservation equations very similar to the ones for the gas. The main advantage is therefore that the gas phas...

Investigation of combustion instabilities in gas turbine combustors require the knowledge of flame transfer functions. Those can be obtained by experimental measurement or by Large Eddy Simulations (LES). Because calculations are usually limited to a portion of the whole combustor, boundary conditions are of crucial importance. It is common practic...

A DNS approach for Eulerian-Eulerian dispersed two phase ∞ows is tested. The need for a subgrid stress term in the dispersed phase momentum equation is identifled and a simple model for this stress term allows the calculation of an experimental test case with inertial particles in homogeneous turbulence. Results are compared to Eulerian- Lagrangian...