Sökresultat:
1418 Uppsatser om Mass flow - Sida 1 av 95
Krafter på rörsystem vid transient flöde : En jämförelse mellan RELAP5 och Fluent
At Forsmarks Kraftgrupp AB (FKA) forces on pipe systems due to transient flow are frequently calculated as a step to verify their structural integrity. In nuclear industries these forces are often calculated with a one dimensional thermal-hydraulic analysis-code called RELAP5. When calculations regarding more complex geometries are needed, the three dimensional code Fluent is often used. This code is highly time consuming and requires large computational power.This projects aim is to compare calculations of pressure, flow and forces carried out by RELAP5 and Fluent for an arbitrary pipe section during transient flow conditions. This has been accomplished by constructing a simple geometry for which a transient flow is simulated in both programs.
Konsekvenser av ny teknik på en sjukhusmottagning
An often encountered problem when implementing a Mass flow regulator in a rolling mill is the one with measurement of speed. The most widely used solution is to fit a pulse counter to a wheel that is in contact with the strip. Common problems with this design are for instance scratch marks on the strip and problems with the flatness measuring system. One way of circumventing the aforementioned problems would be a non-contact measuring system. The market of today only offers systems based on the Doppler principle.This report evaluates three different systems for non-contact speed measurement. Important areas in the evaluation have been the ability to operate under normal rolling conditions, integration in existing control system and how well the sensor can be fitted to the rolling mill.
Val av teknik för hastighetsmätning i kallvalsverk
An often encountered problem when implementing a Mass flow regulator in a rolling mill is the one with measurement of speed. The most widely used solution is to fit a pulse counter to a wheel that is in contact with the strip. Common problems with this design are for instance scratch marks on the strip and problems with the flatness measuring system. One way of circumventing the aforementioned problems would be a non-contact measuring system. The market of today only offers systems based on the Doppler principle.This report evaluates three different systems for non-contact speed measurement. Important areas in the evaluation have been the ability to operate under normal rolling conditions, integration in existing control system and how well the sensor can be fitted to the rolling mill.
Mätning av partikelmassa i avgaser från en dieselmotor
This master thesis was a continuation of a previous study in the diesel exhaust characterization, which is part of the academical work embedded in the EMIR-1 project. The main objective of this thesis work was to finish the installation and make the proper modifications of the particulate mass measuring system located in one of the engine test cells at KTH, in order to be able to measure the mass of the particles from the exhaust of diesel engines.This experiment requires a diluted flow sample from the exhaust that should be sent to the device that makes possible the measurement of particle mass, called TEOM. In the first stage of this project, the objective was to study and make the proper modifications in the existing KTH diluter because there were several problems to obtain a constant dilution ratio from it during tests.This modifications were made and it resulted in a great improvement in the maximum inlet and outlet flow that this diluter can handle. Therefore another modification is proposed for controlling the inlet exhaust flow so it will be possible to regulate the dilution ratio and make it constant along a wide range of engine loads and speeds.The second and most important stage was to make particulate mass measurements possible by analyzing the frequency signal from the TEOM device. The idea was to obtain the frequency of oscillation from the tapered element in the TEOM, and therefore with the proper correlations, be able to predict the particulate mass concentration in the exhaust flow from the engine.An electrical problem in the TEOM circuit was detected and corrected, so the signal that carries the frequency from the TEOM can be analyzed properly.
Mätning av abrasivflöde för vattenskärningsmaskiner
The content of the following report is the summarized result of three students thesis at Blekinge Institute of Technology in co-operation with Water Jet Sweden AB. This report will give the reader a description of principles how to measure the abrasive Mass flow in a waterjet cutting system. The work began with a visit to Water Jet Sweden AB to get a closer look at the problem. When the analysis of the problem was done the criteria were defined in the form of demands and desires. The main task of the criteria was to guide the search for the solution.
Skattning av fordonsmassa med driftstatistik
In the automatic manual transmission system, Opticruise, the choice of gear is based on several parameters such as road incline, driving resistance and vehicle mass. Many different mass estimations are made during driving. A final vehicle mass is then used to determine the current gear. Construction vehicles are often not equipped with air suspension and can therefore not estimate the vehicle mass when standing still. If that sort of vehicle is reloaded while standing still an incorrect mass estimation will be used and as an effect of that also a wrong gear.
Mätning av abrasivflöde för vattenskärningsmaskiner
The content of the following report is the summarized result of three students
thesis at Blekinge Institute of Technology in co-operation with Water Jet
Sweden AB.
This report will give the reader a description of principles how to measure the
abrasive Mass flow in a waterjet cutting system.
The work began with a visit to Water Jet Sweden AB to get a closer look at the
problem. When the analysis of the problem was done the criteria were defined in
the form of demands and desires. The main task of the criteria was to guide the
search for the solution. The work proceeded with an extensive search for
abrasive flow meters along with obtaining information about flow measurement in
general. When the search for abrasive flow meters resulted in nothing all the
efforts were concentrated on finding a principle of measurement that could cope
with the criteria.
Hawkingmassa i Kerr-rumtid
In this thesis we calculate the Hawking mass numerically for surfaces in Kerr spacetime. The Hawking mass is a useful tool for proving the Penrose inequality and the result does not contradict the inequality. It also does not contradict the assumption that the Hawking mass should be monotonic for surfaces in Kerr spacetime. The Hawking mass is quasi-local and defined by the spin coefficents of Newman and Penrose, so first we give a discussion about quasi-local quantities and then a short description of the Newman-Penrose formalism..
Betydelsen av flow i bildskapande och pedagogers betydelse för flow : En uppsats inom bildpedagogik om flow och kreativitet och vilka förutsättningar som gynnar flow.
Uppsatsen behandlar ämnet genus och genusframställningen i barnböcker nu, och för 50 år sedan. För att komma fram till ett resultat har två analysmetoder använts, Nikolajevas mimetiska metod samt en semiotisk bildanalysmetod. Resultatet visar att det skett en förändring av genusframställandet i barnböcker de senaste femtio åren och att den största förändringen skedde i mitten på 60-talet..
Externa kanaler på Prime Care : Tanken med dem, dess funktion och sättet de uppfattas på
AbstractTitle: External communication channels of Prime Care How they where thought to be, how they work and how costumers apprehend them.Number of pages: 50 (64 Including enclosures)Author: Sophie DicksenTutor: Peder Hård af SegerstadCourse: Media- and Communication Studies DPeriod: Spring 2007University: Division of Media and Communication, Department of Information Science, Uppsala UniversityPurpose/Aim: The focus of this paper lies on the external communication channels of Prime Care and the aim is to study the following aspects: How do the channels work? How are they apprehended by customers of the company? What are Prime Cares own thoughts behind the channels? How does Prime Cares self-image correspond to the way that customers apprehend the company?Material/Method: Twenty interviews has been done with different customers of Prime Care in order to see how the company and its communication flow is apprehended. A consultant manager of Prime Care has also been asked about purposes behind the companies external communication channels in order to enable a comparison between Prime Cares image and profile. Prime Cares website, one of their mail sendouts, their salescalls, salesvisits and their exhibition participation have been studied on the basis of relevant litterature. Maletzkes model of mass communication was used as a general view of communication flow.Main results: All communication channels included in this study have different ways of function even though they all have the same main purpose, videlicet to promote the company, to inform about its activities and to recruit new customers and consultants.
How streaming media can be used in commercial mass
distribution
Mass distribution with techniques as multicast and peer-to-peer are becoming increasingly important in the Internet. Today the distribution of sound and video over Internet, so called streaming media, is static due to the unicast method. This results in a linear increase of distribution costs and therefore no conditions for commercial scalability. This thesis describes why multicast may be the only scalable alternative for commercial mass distribution of streaming media over Internet. Mass distribution through peer-to-peer technology promises a lot but is fronting a couple of great challenges, for example asymmetric bandwidth, locality and legalization.
Modellering av ett bränslesystem i Modelica : tillämpat på ett obemannat flygplan
Mathematical models possible to simulate are of great importance in order to make successful projects in the aircraft manufacturing industry. An aircraft fuel system is very complex, containing pipes, tanks, orifices, valves and pumps. The principal of this thesis is using the tool Easy5, which no longer is considered reliable enough in terms of development and support. This thesis tries to evaluate the Modelica language as a possible alternative to Easy5. To make this evaluation, the components concerned in the fuel library in Easy5 are implemented to the Modelica language.
Transporttider för vatten i närområdet till en vattentäkt : spårämnesförsök i en isälvsavlagring
When establishing a groundwater protection area it is of great interest to be able to estimate the transit time of the groundwater from different places of the aquifer to the withdrawal well. These estimates can be uncertain due to heterogeneities in the aquifer. As a part of the work to develop methods for a more certain delineation of protection areas, a tracer test was performed in an esker located 25 kilometres NW of the town Uppsala.The purpose of this master thesis was to perform, describe and evaluate the tracer test. Travel times from the tracer test should then enable comparison against stochastic simulated travel times of the groundwater in the area.Three dyes (rhodamine WT, uranine and naphtionate) and a salt (NaBr) were used in the tracer test. The tracers were injected in four different wells located 25 meters from a pumping well.
Näringsbelastning på en anlagd våtmark från åker, skog och enskilda avlopp :
This work is a part of the project ?Våtmarker i odlingslandskapet ? uppföljning av miljömålen? (Wetlands in arable land ? following-up of the environmental goals). The main objective with this project is to study nitrogen and phosphorus retention in a constructed wetland by using mass balance calculations. Continuous measurements of nutrients and water flow through the inlet and the outlet of the wetland are made. However, substantial amounts of nitrogen and phosphorus were assumed to reach the wetland with a drain-pipe transporting wastewater from nearby houses (10 persons).
Dynamisk massbalansmodellering av fosfor i Östersjön
During the past few years a vast amount of research has been done to increase the understanding of the complex ecosystem of the Baltic Sea. Modelling and simulations are important tools to increase knowledge of the system. A suitable model must be simple to use and the parameters and variables needed in the model must be easy to access.In this paper a dynamical mass-balance model, CoastMab, which is validated for smaller coastal areas, has been used to predict concentrations and transports of phosphorus in three large coastal areas - the Gulf of Finland, the Gulf of Gdansk and the Gulf of Riga. CoastMab uses ordinary differential equations to regulate inflow, outflow and internal flows. To reflect seasonal variations in temperature and different types of flows the model has a temporal resolution of a month.