Poster auf der Frühjahrstagung der Deutschen Physikalischen Gesellschaft, Regensburg März 2025

E. Eisenschmidt, J.A. Schmidt,B. Schmidt, A. Schirmeisen, H. Weisweiler

„Dynamic Temperature and Mass Flow Measurements in the Cold End of a Single Stage GM-Type Pulse Tube Cooler“

Darstellung von Messergebnissen und vergleichenden Simulationsresultaten für einen Single Stage GM-Type Pulse Tube Cooler aus einer Kooperation von Prof. Dr.  André Schirmeisen (JLU, Inst. f. Angewandte Physik,CryoTransmit) und Prof. Dr. Hardy Weisweiler (THM, Fachbereich M,Labor für Strömungstechnik und Mechanik)

Tagung der Deutschen Physikalischen Gesellschaft DPG, Berlin, 20. März 2024 

Auf der Frühjahrstagung der Deutschen Physikalischen Gesellschaft (Berlin, März 2024) wurden einige Ergebnisse aus der Zusammenarbeit mit dem Institut für angewandte Physik (Direktor Prof. Dr. Schirmeisen), JLU bzw. TransMIT-Zentrum für adaptive Kryotechnok und Sensorik in einem Vortrag publiziert:

Thema des Vortrages:
Experimental investigations and numerical simulations of the pressure drop in different regenerator fillings of a single stage GM-type pulse tube cooler

Elias Eisenschmidt^1,3, Jack-Andre Schmidt^2,3, Bernd Schmidt^2,3, Jens Falter³, HARDY WEiSWEILER ⁴, Andre Schirmeisen²

Im Vortrag wurden Strömungssimulationsergebnisse und Messungen an einem Pulsrohrkühler (PTS 8030, TransMIT GmbH) präsentiert. Ziel der Untersuchungen waren u.a. die Druckverluste in verschiedenen Regenerator-Füllungen. Insbesondere die numerischen Simulationen erlauben einen detailierteren Einblick in die Strömungssituation im Inneren.

Die Ergebnisse der Experimente können zum Beispiel für die Simulation des gesamten Kühlers dienen. Zwar wurden in anderen Publikationen ähnliche Simulationen präsentiert, dort jedoch nur mit vereinfachenden harmonisch variierenden Massen- und Druckverläufen. Unter Verwendung der Messungen als Eingabebedingungen wurden im Vergleich realitätsnähere Simulationen der Situation im Inneren des Kühlers durchgeführt.

Frühjahrstagung der Deutschen Physikalischen Gesellschaft (26.-31. März 2023) 

Auf der Frühjahrstagung der Deutschen Physikalischen Gesellschaft (26.-31. März 2023)
wurden einige Ergebnisse aus der Zusammenarbeit mit dem Institut für angewandte Physik (Direktor Prof. Dr. Schirmeisen), JLU bzw. TransMIT-Zentrum für adaptive Kryotechnok und Sensorik
in einem Poster publiziert:

AIP Conference Proceedings Published Online 2020
"Underexpanded free and confined jet structures: CFD simulations" (Weisweiler/Kojouharova)

https://ui.adsabs.harvard.edu/abs/2020AIPC.2293P0031W/abstract

Underexpanded free and confined jet structures: CFD simulations

AIP Conference Proceedings 2293, 420031 (2020); https://doi.org/10.1063/5.0026720

Hardy Weisweiler and  Jasmina Kojouharova (Department of Mechanical Engineering, Mechatronics and Materials Technology THM University of Applied Sciences, Wilhelm-Leuschner-Str. 13, 61169 Friedberg, Germany)

 DOI: 10.1063/5.0026720

Bibcode: 2020AIPC.2293P0031W

Originalbericht

MATEC Web of Conferences (2018)
"Design of short low speed Göttingen type wind tunnel: CFD simulation" (Weisweiler/Kojouharova/Dückershoff)

Abstract

The paper is focused on design simulations by the means of commercial software for a low speed circuit wind tunnel with an open test section, recently built at the Department of Mechanical Engineering, Mechatronics and Materials Technology at THM University of Applied Sciences in Friedberg. The proposed wind tunnel has a test section with cross sectional area of 1 X 1 m2 and a length of 1.6 m. The maximum achievable speed is about 50 m/s with empty test section. The simulation had the target to propose and to verify various geometries - test chamber, tunnel contraction, diffuser etc. as well the tunnel corner including the vanes. In addition, the influence of the vanes number and their shape on the ventilator power needed and the flow velocity uniformity as well, have been subjects of the investigation. Also the ventilator type (rotational segment) impact on the flow pattern within the operational area has been scrutinized.

Originalbericht

13th National Congress on Theoretical and Applied Mechanics (NCTAM 2017)
"Vortrag zur Simulation der Strömung in einem Windkanal" (Kojouharova/Weisweiler)

MATEC Web of Conferences Volume 145 (2018)

Sofia, Bulgaria
6 - 10 September 2017

Vortrag zur Simulation der Strömung in einem Windkanal

AIP Conference Proceedings (2015)
"Modelling of fully separated flow past a circular cylinder: Problems and best practice" (Kojouharova/Weisweiler)

https://ui.adsabs.harvard.edu/abs/2015AIPC.1684g0003K/abstract

AIP Conference Proceedings 1684, 070003 (2015); https://doi.org/10.1063/1.4934304

Abstract

This paper gives a draft overview of the elaborated strategy for a reliable simulation of a subcritical incompressible viscous flow past a circular cylinder by the means of the commercial Software ANSYS CFX. It is motivated by its relevance to serve as a general flow prototype past a bluff body, which is an issue of considerable engineering interest, and is focused on the computational specifics of the topic. The flow separation is investigated by the means available in the ANSYS CFX Reynolds Averaged Navier-Stokes Simulations (RANS) method as the Shear Stress Transport model is employed.

Originalbericht

Neues und umweltfreundliches Entölungsverfahren durch Niederdruck-Verdampfung

Vakuum in Forschung und Praxis 7 84) 269-274 January 1995, doi: 10.1002/vipr.19950070406

Abstract

Ecologically beneficial processes for deoiling metallic or plastic parts to be coated or brazzed gain more and more importance. Especially the low‐pressure evaporation process shows recognizable advantages. The oily parts or devices are cleaned at medium temperature and at process‐pressures of less than 0.1 mbar from the adhered machine oil. In opposite to liquid deoiling procedures also complete assembled devices can be treated in one process step only. Joined plasma processes activate or modify the surfaces for decoration or functional coatings. In the following contribution the process‐technology and machine design is explained and as an example a vacuum‐deoiling plant for automotive heat exchangers is presented.

Originalbericht

Decoupling of processes in coating systems by pumped buffers

ScienceDirect, https://doi.org/10.1016/0042-207X(88)90441-1

Abstract

 In order to separate processes in coating systems where substrates are transported by carriers, vacuum locks and lock chambers are mainly used at present. As will be shown in this paper process decoupling can also be achieved by the use of pumped buffers. Besides excellent separation, pumped buffers furthermore allow a continuous coating operation and a maximum of productivity. In this report measured and calculated separation features will be presented concerning a buffer system consisting of three pumped chambers. Several cases are regarded, the system with and without carriers, with moved and static carriers. It is shown that without carriers only 1/20,000 of the pressure changes of the regarded coating-chamber could be detected in the second coating chamber separated by the buffer. In the case of moving carriers it will be shown that less than 1/10⁶ of the pressure change occurs in the second coating chamber.

Originalbericht