New High-Performance Gas Flow Equalizing Metal Supports for Automotive Exhaust Gas Catalysts

1990 ◽  
Author(s):  
Manfred Nonnenmann
Keyword(s):  
High Performance ◽  
Gas Flow ◽  
Exhaust Gas ◽  
Automotive Exhaust ◽  
Metal Supports

High Performance MEMS Thermal Gyroscope

2012 ◽  
Author(s):  
Nilgoon Zarei ◽  
Albert M. Leung ◽  
John D. Jones
Keyword(s):  
External Force ◽  
High Performance ◽  
Gas Flow ◽  
Element Model ◽  
Minimal Impact ◽  
Mems Gyroscope ◽  
Force Finding ◽  
Dimensional Finite Element ◽  
To Come ◽  
The Impact

This paper reports modeling a new design of Thermal MEMS gyroscope through the use of the Comsol Multiphysics software package. Being very small and having no movable parts have made thermal MEMS gyroscope very practical. Previously designed Thermal MEMS gyroscope shows some limitation such as being vulnerable to gravity force. Finding a technique to increase the range of thermal MEMS gyroscope reliability motivated us to come up with a new design that we will refer to as the ‘Forced Convection MEMS gyroscope’. A two-dimensional finite-element model of the device has been developed to investigate its performance. An external force has been introduced to the system to create a higher-velocity hot gas stream that will be deviated more in response to rotation. The external force should be great enough that convection currents resulting from gravity or acceleration will have minimal impact on the gyroscope sensitivity. A heating element can still be used, but its primary purpose is now to warm the flowing gas so that it can be detected by the sensors. In this paper we will also show that, in order to completely eliminate the impact of gravity and increase the sensitivity of the gyroscope, it is possible to eliminate the heaters entirely and instead use heated sensors to detect gas currents. In other words, the sensors are working as hot-wire anemometers. Our simulations suggest that this design variant results in higher sensitivity. We have also carried out optimization studies to identify the best location for the heaters and sensors. A prototype of this device has been fabricated based on MEMS techniques, and an external pump is used to produce an oscillating gas flow within the device.

Effect of ejector dilutors on measurements of automotive exhaust gas aerosol size distributions

2009 ◽  
Vol 20 (4) ◽  
pp. 045703 ◽  
Author(s):  
Barouch Giechaskiel ◽  
Leonidas Ntziachristos ◽  
Zissis Samaras
Keyword(s):  
Exhaust Gas ◽  
Size Distributions ◽  
Automotive Exhaust

scholarly journals Preparation of isocyanates by carbamates thermolysis on the example of butyl isocyanate

2019 ◽  
Vol 58 (4) ◽  
pp. 40-47
Author(s):  
Ratmir R. Dashkin ◽  
◽  
Dmitry A. Gordeev ◽  
Khusrav Kh. Gafurov ◽  
Sergey N. Mantrov ◽  
...  
Keyword(s):  
Gas Phase ◽  
High Performance ◽  
Gas Flow ◽  
Flow Reactor ◽  
Packed Column ◽  
Biologically Active ◽  
Dibutyltin Dilaurate ◽  
Reaction Products ◽  
Uv Detector ◽  
Laboratory Setup

Butyl isocyanate is widely distributed as a precursor for the production of a number of biologically active substances: fungicides, preservatives, insecticides, personal care products, etc. Nowadays, there are a number of methods for the preparation of isocyanates, which can be divided into liquid phase and gas phase. One of the perspective methods for the production of isocyanates is the thermolysis of carbamate and/or the actions of various reaction activating agents, accompanied by the elimination of alcohol, but this process is reversible, which greatly complicates its use in industry. The paper presents the results of studies of non-catalytic thermal decomposition of N-alkylcarbamates with the formation of alkylisocyanates on the example of butylisocyanate in the gas phase, flow reactor in a wide temperature range (200 to 450 °C). In addition, a series of experiments was carried out using a catalyst, dibutyltin dilaurate, in order to reduce the thermolysis temperature and increase the yield of the final product. To implement the isocyanate production process, an experimental laboratory setup, consisting of a gas flow meter (argon) regulator, a packed column (for heating) and a sorption solution tank, was developed and tested. The thermolysis of N-n-butylcarbamate was carried out in two variations: the preparation of an individual n-butylisocyanate and the passage of reaction products through a sorption solution linking the n-butyl isocyanate to N-n-butyl-N '-(1-phenylethyl)urea, which allows to estimate the yield of the target n-butylisocyanate without additional losses. The analysis of the obtained substances was carried out by high performance liquid chromatography with a UV detector (target product) and a mass detector (analysis of by-products). According to the results of research, a modification of the laboratory facility was proposed, as well as n-butylisocyanate was obtained with a yield of 49% on the basis of a new technique.

scholarly journals Exhaust Gas Flow Measurement System - CRADA Final Report

1997 ◽  
Author(s):  
J Hardy ◽  
R Abston ◽  
J Hylton ◽  
T McKnight ◽  
R Joy ◽  
...  
Keyword(s):  
Measurement System ◽  
Flow Measurement ◽  
Gas Flow ◽  
Final Report ◽  
Exhaust Gas

scholarly journals 1D–3D Coupling Algorithm of Gas Flow for the Valve System in a Compression Ignition Engine

2021 ◽  
Vol 9 (10) ◽  
pp. 1061
Author(s):  
Kyeong-Ju Kong
Keyword(s):  
Gas Flow ◽  
Flow Analysis ◽  
Emission Control ◽  
Experimental Results ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Valve System ◽  
Ci Engine ◽  
Control Devices ◽  
Coupling Algorithm

Emission control devices such as selective catalytic reduction (SCR), exhaust gas recirculation (EGR), and scrubbers were installed in the compression ignition (CI) engine, and flow analysis of intake air and exhaust gas was required to predict the performance of the CI engine and emission control devices. In order to analyze such gas flow, it was inefficient to comprehensively analyze the engine’s cylinder and intake/exhaust systems because it takes a lot of computation time. Therefore, there is a need for a method that can quickly calculate the gas flow of the CI engine in order to shorten the development process of emission control devices. It can be efficient and quickly calculated if only the parts that require detailed observation among the intake/exhaust gas flow of the CI engine are analyzed in a 3D approach and the rest are analyzed in a 1D approach. In this study, an algorithm for gas flow analysis was developed by coupling 1D and 3D in the valve systems and comparing with experimental results for validation. Analyzing the intake/exhaust gas flow of the CI engine in a 3D approach took about 7 days for computation, but using the developed 1D–3D coupling algorithm, it could be computed within 30 min. Compared with the experimental results, the exhaust pipe pressure occurred an error within 1.80%, confirming the accuracy and it was possible to observe the detailed flow by showing the contour results for the part analyzed in the 3D zone. As a result, it was possible to accurately and quickly calculate the gas flow of the CI engine using the 1D–3D coupling algorithm applied to the valve system, and it was expected that it can be used to shorten the process for analyzing emission control devices, including predicting the performance of the CI engine.

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