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Erlangen, Germany

Dongari N.,University of Strathclyde | Durst F.,FMP Technology GmbH | Chakraborty S.,Indian Institute of Technology Kharagpur
Microfluidics and Nanofluidics | Year: 2010

We test an extended continuum-based approach for analyzing micro-scale gas flows over a wide range of Knudsen number and Mach number. In this approach, additional terms are invoked in the constitutive relations of Navier-Stokes-Fourier equations, which originate from the considerations of phoretic motion as triggered by strong local gradients of density and/or temperature. Such augmented considerations are shown to implicitly take care of the complexities in the flow physics in a thermo-physically consistent sense, so that no special boundary treatment becomes necessary to address phenomenon such as Knudsen paradox. The transition regime gas flows, which are otherwise to be addressed through computationally intensive molecular simulations, become well tractable within the extended quasi-continuum framework without necessitaing the use of any fitting parameters. Rigorous comparisons with direct simulation Monte Carlo (DSMC) computations and experimental results support this conjecture for cases of isothermal pressure driven gas flows and high Mach number shock wave flows through rectangular microchannels. © Springer-Verlag 2010. Source


Epple Ph.,Friedrich - Alexander - University, Erlangen - Nuremberg | Durst F.,FMP Technology GmbH | Delgado A.,Friedrich - Alexander - University, Erlangen - Nuremberg
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science | Year: 2011

The design of high-efficiency fans is often based on the experience of the designer. In order to determine its main dimensions, fan designers use the Cordier diagram. For a given operating point (i.e. flowrate and pressure, and a rotating speed), the optimum diameter of high-efficiency fans can be found in the Cordier diagram. The Cordier diagram is an empirical diagram based on measurements. It delivers a relation between flowrate, pressure, rotating speed, and diameter. However, the Cordier diagram does not provide any information on the blade shape (i.e. the angles and the blade width). In order to fill this gap, there are design rules based on the experience of the designer and some analytical performance parameters in the literature. One very common performance parameter is the reaction, which is the ratio between the static and the total pressure rising from the impeller inlet to its outlet. These design rules and performance parameters are, however, of limited use. Therefore, the total-to-static ideal efficiency is introduced to yield, together with the speed and diameter numbers σ and δ, the essential parameters that distinguish the different turbomachines in the Cordier diagram. Based on the integral parameters of the flow and the geometry of turbomachines, a performance analysis of turbomachines is performed and the Cordier diagram is theoretically derived. Source


Durst H.C.F.,FMP Technology GmbH | Gillert M.,FMP Technology GmbH
Coating International | Year: 2010

FMP TECHNOLOGY GMBH applies submicro-layers from liquid solutions as liquid coats. Coating of web-form films, metals, textiles, papers, etc. products like glass, semiconductor wafer, wood, plastic sheets, etc. will all be possible that way. The special feature of the coat application investigated here is that wet film thicknesses only present with a few microns in thickness, something that was previously thought of as impossible to realise with slot dies. The coating technology for these thin layers, however, requires special skills and the slot dies used must take into consideration specific features that, with large application quantities (i.e. high layer thickness) do not need to be considered in dealing with the slot dies used, in order to ensure a high level of transverse distribution accuracy. FMP TECHNOLOGY GMBH has set up a special in-house coating engineering section in order to advance development of the technology used to produce thin wet coats on substrates. The laboratory facilities that thus have become necessary were able to be created or modified so that the special properties presented by thin layers will be taken into account in the experiments that are being carried out. The works were successfully completed a few days ago, so that it will now be possible to practically implement the knowledge obtained in a target-oriented manner. This brief report is intended to serve as information about this development. Source


Wegener M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Roosen A.,Friedrich - Alexander - University, Erlangen - Nuremberg | Gillert M.,FMP Technology GmbH | Durst F.,FMP Technology GmbH
CFI Ceramic Forum International | Year: 2013

To summarize, the slot die coating can be described as a suitable process for the fabrication of laminar ceramic films in the submicrometre range. The volume flow control and the high uniform distribution accuracy of the slot die enables the application of coatings with very high quality at high coating rates. A flexible substrate was continuously coated with the slurry, based on ITO nanoparticles, with wet film coatings up to 5 urn. From this resulted a dried ITO coating of 300 nm. The performance with regard to transmission and conductivity of these coatings corresponds to that of profiled doctor blade coatings, which, however, were applied at much lower coating rates. Defect-free, highly accurate coating of suspensions prepared from ceramic powders on substrates such as film, glass, etc. requires reliably and universally functioning coating tools and also demands simple and fast operability during the run-in process and retooling as well as the costeffective operation of the machine on test or production scale. Source


Gillert M.,FMP Technology GmbH | Brauckmann O.,Mehler Engineered Products GmbH | Spielmann D.,Mehler Engineered Products GmbH | Durst F.,FMP Technology GmbH
Coating International | Year: 2015

This publication summarizes development work, which has been carried out by the companies FMP Technology GmbH and Mehler Engineered Products GmbH in order to allow for improved and faster coatings of fibres, yarns and threads. The result of these developments was the ring slot die coating technology described in this paper. It summarizes design considerations, which were carried out to yield a strategy to lay out ring slot dies for fibres, yarns and threads. One ring slot die is described in the paper resulting from these developments and its employments in preliminary tests are reported. Due to the nature of the system, coating rates of up to 300 m/min have been realized during the development work. This speed does not correspond to the maximum coating speed, according to the authors' opinion. Source

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