Numerical Simulations of Unsteady Aerodynamic Effects in the Blade Tip Region of Cooling Fans

2016 ◽  
Author(s):  
Gi-Don Na ◽  
Frank Kameier ◽  
Nils Springer ◽  
Michael Mauß
Keyword(s):  
Applied Sciences ◽  
Numerical Simulations ◽  
Aerodynamic Performance ◽  
Secondary Flows ◽  
Acoustic Measurements ◽  
Noise Emission ◽  
Industrial Partner ◽  
University Of Applied Sciences ◽  
Blade Tip ◽  
The University

The acoustical characteristics of fans are an essential criterion of product quality and are continually growing in importance as for example cooling fan modules in the automotive industry have to suffice high comfort requirements. In order to locate dominant acoustic sources and to reduce the noise emission generated by a shrouded fan configuration, numerical simulations are performed. The working approach considers variously modified fan geometries and their evaluation regarding arising vortex flow phenomena and their effect on a decreased sound pressure level (SPL) in consideration of an improvement or the constancy of aerodynamic fan performance. Particular emphasis lies on the analysis of secondary flows in the blade tip region by postprocessing CFD-results. Due to the large number of geometrical modifications investigated and the importance of highly resolved eddy structures, a hybrid approach is chosen by applying the SAS-SST turbulence model in URANS simulations. The SAS (Scale Adaptive Simulation) delivers LES (Large Eddy Simulation) content in unsteady regions of a RANS-simulation and exhibits not nearly the high computational effort needed to perform a full scale LES. An assessment of the actual propagation of noise emission into the far-field is made by performing experimental investigations on the most promising modifications. The acoustic measurements are carried out in a fan test stand in the anechoic chamber of the University of Applied Sciences Duesseldorf. The aerodynamic performance is measured in a fan test rig with an inlet chamber setup in accordance with ISO 5801. The measured acoustical and aerodynamic performance is validated by the industrial partner. The results of the acoustic measurements are in turn utilized to determine indicators of noise radiation in the numerical simulation. Within this work an approach is presented where the analyses of secondary flows in the blade tip region provide the basis for an innovative noise reduction design in a shrouded fan configuration. The new design exhibits a reduced SPL (A-weighted) of approx. 4 dB over the entire operating range while showing no significant deterioration on the aerodynamic performance. The design was registered for patent approval cooperatively by the industrial partner and the University of Applied Sciences Duesseldorf, while minor design parameters are still subject to further improvements. All numerical simulations are performed with Ansys CFX, a commercial solver widely spread in the industry. Methods similar to those shown in this work can be implemented in the design phase of axial fans in order to develop acoustically optimized fan geometries.

URANS Simulations and Experimental Investigations on Unsteady Aerodynamic Effects in the Blade Tip Region of a Shrouded Fan Configuration

2017 ◽  
Author(s):  
Gi-Don Na ◽  
Frank Kameier ◽  
Nils Springer ◽  
Michael Mauß ◽  
C. O. Paschereit
Keyword(s):  
Applied Sciences ◽  
Numerical Simulations ◽  
Aerodynamic Performance ◽  
Design Parameters ◽  
Experimental Investigations ◽  
Acoustic Measurements ◽  
Noise Emission ◽  
Industrial Partner ◽  
University Of Applied Sciences ◽  
Blade Tip

The acoustical characteristics of cooling fans are an essential criterion of product quality in the automotive industry. Fan modules have to suffice growing customer expectations which are reflected in the comfort requirements set by car manufacturers around the world. In order to locate dominant acoustic sources and to reduce the noise emission generated by a shrouded fan configuration, numerical simulations and experimental investigations are performed. The working approach considers variously modified fan geometries and their evaluation regarding arising vortex flow phenomena and their effect on a decreased sound pressure level (SPL) in consideration of an improvement or the constancy of aerodynamic fan performance. Particular emphasis lies on the analysis of secondary flows in the blade tip region by post-processing CFD-results. Due to the large number of geometrical modifications investigated and the importance of highly resolved eddy structures, a hybrid approach is chosen by applying the SAS-SST turbulence model in URANS simulations. The SAS (Scale Adaptive Simulation) delivers LES (Large Eddy Simulation) content in unsteady regions of a RANS-simulation and exhibits not nearly the high computational effort needed to perform a full scale LES. An assessment of the actual propagation of noise emission into the far-field is made by performing experimental investigations on the most promising modifications. The acoustic measurements are carried out in a fan test stand in the anechoic chamber of Duesseldorf University of Applied Sciences. The aerodynamic performance is measured in a fan test rig with an inlet chamber setup in accordance to ISO 5801. The measured acoustical and aerodynamic performances are validated by the industrial partner. The results of the acoustic measurements are in turn utilized to determine indicators of noise radiation in the numerical simulation. Within this work an innovative geometry modification is presented which can be implemented into shrouded fan configurations with backward-skewed blades. The new design exhibits a reduced SPL (A-weighted) of approx. 4 dB over the entire operating range while showing no significant deterioration on the aerodynamic performance. While the design was registered for patent approval cooperatively by the industrial partner and Duesseldorf University of Applied Sciences, further investigations regarding variations of design parameters are performed and presented in this paper. All numerical simulations are performed with ANSYS CFX, a commercial solver widely spread in the industry. Methods similar to those shown in this work can be implemented in the design phase of axial fans in order to develop acoustically optimized fan geometries.

scholarly journals Auditing in a Family-Centered Higher Education Institution: The German Experience of Implementation

2021 ◽  
Vol 21 (3) ◽  
pp. 21-25
Author(s):  
Susanne Maier ◽  
Keyword(s):  
Applied Sciences ◽  
Higher Education ◽  
Public Administration ◽  
Education Institution ◽  
Working Environment ◽  
Family Friendly ◽  
The Family ◽  
University Of Applied Sciences ◽  
The University ◽  
Family Centered

The family-friendly university audit (“audit familiengerechte hochschule”) is studied. The audit is available to German universities in order to support a familyfriendly working environment. Practices of an auditor coordinating several workshops for rectorate, HR department and functionaries, as well as representatives of all university groups are considered. The experience of the auditing at the University of Applied Sciences – Public Administration and Finance, Ludwigsburg is analyzed.

scholarly journals Multikodalität und Digitales Lehren und Lernen

2021 ◽  
Keyword(s):  
Applied Sciences ◽  
Intercultural Communication ◽  
Teaching And Learning ◽  
Language Teaching ◽  
Special Role ◽  
Master's Program ◽  
Multimedia Teaching ◽  
University Of Applied Sciences ◽  
Training Courses ◽  
The University

Nothing has highlighted the importance of digital teaching and learning opportunities more obviously than the Corona pandemic. This book therefore focuses on multicodal or multimedia digital teaching. The authors examine it from various perspectives and make suggestions for successful didactic implementation. In addition to general topics of digital teaching, they devote particular attention to visual literacy, which plays a special role in multimedia teaching. Criticism of teachers' lack of digital skills alone will not lead to success. Therefore, ways are shown here how these skills can be acquired. Tips and concrete examples for suitable apps, serious games, and online training courses round off the volume. Christina Maria Ersch is a staff member/DaF coordinator at the International Office of the University of Applied Sciences Mainz and lecturer at the University of Mainz. Her research interests lie in (university) didactics, especially in the implementation of competence orientation and digitalization of teaching of teaching, intercultural communication, and the influence of emotions in of emotions in (foreign language) teaching. Dr. Marion Grein is head of the Master's program DaF/DaZ at the the University of Mainz. Her work focuses on language teaching research (neurodidactics), intercultural communication, and digital teaching.

scholarly journals The importance of formal grammar skills: Reflections on Polish students learning Norwegian

2018 ◽  
pp. 107-132
Author(s):  
Jens Haugan
Keyword(s):  
Applied Sciences ◽  
Language Education ◽  
Formal Grammar ◽  
Language Teacher Education ◽  
Educational Role ◽  
University Of Applied Sciences ◽  
Scandinavian Language ◽  
The University ◽  
Language Network

Norwegian and Scandinavian languages in general have grown quite popular among Polish students in recent years and more and more Polish universities are trying to offer Bachelor’s and even Master’s programmes in a Scandinavian language. Based on experience as a teacher of a Norwegian grammar course at the University of Szczecin and as a teacher of grammar at the Inland Norway University of Applied Sciences which in 2016/2017 hosted around twenty Erasmus+ students from Szczecin, some of the challenges for Polish students of academic Norwegian will be reflected upon, as well as some of the challenges for a teacher of Norwegian who has very little knowledge of Polish. The main purpose of this paper will be to argue for the importance of grammar skills in language education and especially in language teacher education. This study is a contribution to the Educational Role of Language network.

Phenomenology and Conversational Analysis in Communicology and Translatology – A Progress Report

2018 ◽  
pp. 271-290
Author(s):  
Romina Mählmann ◽  
John Wrae Stanley
Keyword(s):  
Applied Sciences ◽  
Role Play ◽  
Progress Report ◽  
Phenomenological Method ◽  
Conversational Analysis ◽  
Job Interview ◽  
University Of Applied Sciences ◽  
German Speaking ◽  
The University ◽  
Introductory Phase

This is a report on the initial efforts made to develop phenomenological and hermeneutical methods for didactical use and epistemological research in communicology and translatology. The following analysis deals with a face-to-faceinteraction workshop that took place at the University of Applied Sciences Cologne in January 2012. The primary goal of this workshop was to establish whether or not an adaptation of the Husserlian phenomenological method could be applied within the framework of role plays, i.e., to see to what extent the phenomenological method makes it possible to observe oneself reflectively while actively participating in role plays. In toto, 14 English and German speaking participants took part in different role plays simulating the job-interview process. For this purpose the phenomenological and hermeneutical methods were explicated in an introductory phase and – at least at a rudimentary level – employed in the role plays. During the role plays, the primary tool employed to disclose verbal, para-verbal and non-verbal phenomena used in communication was the phenomenological method. After the role plays, a hermeneutical analysis was done in one selected group. The participants involved were asked to talk about the experiences they made during the role play; this was done while watching a video of the role plays, and it was designed to access the meaning of various verbal, para-verbal and non-verbal phenomena. Especially the comparison of their feelings, thoughts and perceptions with those of other participants was quite informative.

scholarly journals Automatization of membrane contactors and applications for the management of dissolved gases in wines

2019 ◽  
Vol 15 ◽  
pp. 02037
Author(s):  
P. Schonenberger ◽  
J. Ducruet ◽  
A. Pernet ◽  
F. Marsan ◽  
B. Bach ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Wine Industry ◽  
Small Scale ◽  
Dissolved Gases ◽  
University Of Applied Sciences ◽  
Exact Exchange ◽  
Internal Pressures ◽  
The University ◽  
Membrane Contactors ◽  
Alcohol Reduction

Over the last decade, several distinct research groups tested possible uses of membrane contactors for the wine industry, notably for the management of dissolved gases in wines, adjustment of the CO2 concentration while reducing the O2 concentration at the same time. Other experiments were done with partial alcohol reduction and addition of N2 to wines. The contactor's heart is its Liqui-Cel™ membrane where the two separate circuits meet. The membrane's hydrophobic characteristics allows a liquid to get in contact with a gas, without dispersing into it. The directions that these gases take through the membrane depend on their partial pressure differences within the two circuits. However, other factors need to be considered to determine exact exchange rates for each target gas. The present article describes the new membrane contactor prototype that was co-developed by the University of applied Sciences and Arts, Viticulture and Enology at Changins, Switzerland, and the School of Engineering and Architecture at Fribourg, Switzerland. The prototype was designed for small scale operations. Flow rates, temperatures and internal pressures can be instantly measured and graphically visualized. Also, O2 concentrations are measured inside the liquid. CO2 concentrations in the liquid can be measured with a device that is connected to the liquid circuit through a bypass after the membranes.

Experimental Investigations inside the Wind Tunnel at the University of Stralsund

2016 ◽  
Vol 831 ◽  
pp. 117-125
Author(s):  
Thomas Panten ◽  
Heiko Meironke
Keyword(s):  
Applied Sciences ◽  
Wind Tunnel ◽  
Particle Image ◽  
Velocity Fields ◽  
Experimental Investigations ◽  
Wake Structure ◽  
Image Velocimetry ◽  
University Of Applied Sciences ◽  
Simple Body ◽  
The University

In this paper the wind tunnel at the University of Applied Sciences Stralsund and few construction details as well as the calibration of the nozzle are presented. Furthermore some approaches to visualization and measurement of velocity fields of a simple body of vehicle are shown. The wake structure behind of simple car models was investigated experimentally using Particle Image Velocimetry (PIV). Furthermore the visualization of flow field by the fog probe systems supports the evaluation of the flow and drag behavior.

Feasibility Study of a Recuperated Turboshaft-Engine Based on a Micro-Gasturbine

2009 ◽  
Author(s):  
Clemens Harr ◽  
Ulrich Ga¨rtner ◽  
C. Oliver Paschereit
Keyword(s):  
Applied Sciences ◽  
Feasibility Study ◽  
Current State ◽  
Power Turbine ◽  
Phase Cycle ◽  
University Of Applied Sciences ◽  
Shaft Power ◽  
Previous Design ◽  
Turboshaft Engine ◽  
The University

The present paper shows the current state of a feasibility study of the University of Applied Sciences Esslingen. The intention of this study is the conversion of a model-turbine into a turboshaft-engine for variable applications, with as few as possible modifications. The shaft power of the engine is estimated on 20 kW at least. It is intended to use a recuperator to augment its efficiency. After a general introduction possible applications are discussed and the previous design-process is explained: Subsequent to the concept-phase cycle parameters were calculated and the power turbine was designed and manufactured. At present turbine tests are running. The recuperator is of counter flow type. To shorten the flow path it is mounted directly around the combustor. Currently different variations are being designed which will be optimised. The pressure loss within the exhaust manifold between power turbine and recuperator has already been reduced by simulations and tests. This will be minimised through application of a genetic optimisation software.

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