<p>In this master\2019s thesis work, research has been carried out to develop an automated and parameterized programming model in Matlab to generate a standard journal file, which can read by Gambit and produce a meshed 2D and 3D blade. This file then can be exported into mesh-formatted file for fluent for further simulations and numerical results.</p>

In this master\2019s thesis work, research has been carried out to develop an automated and parameterized programming model in Matlab to generate a standard journal file, which can read by Gambit and produce a meshed 2D and 3D blade. This file then can be exported into mesh-formatted file for fluent for further simulations and numerical results.

The Very High Temperature Reactor (VHTR) system behavior should be predicted during normal operating conditions and during transient conditions. To predict the VHTR system behavior there is an urgent need for development, testing and validation of design tools to demonstrate the feasibility of the design concepts and guide the improvement of the plant components. One of the identified design issues for the gas-cooled reactor is the thermal mixing of the coolant exiting the core into the outlet plenum. Incomplete thermal mixing may give rise to thermal stresses in the downstream components. This analysis was performed by coupling a RELAP5-3D© VHTR model to a Fluent outlet plenum model. The RELAP5 VHTR model outlet conditions provide the inlet boundary conditions to the Fluent outlet plenum model. By coupling the two codes in this manner, the important three-dimensional flow effects in the outlet plenum are well modeled without having to model the entire reactor with a computationally expensive code such as Fluent. The two codes were successfully coupled. The values of pressure, mass flow rate and temperature across the coupled boundary showed only slight differences. The coupling tool used in this analysis can be applied to many different cases requiring detailed three-dimensional modeling in a small portion of the domain.

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. Forces have been calculated via pressure difference over the pipe section and also by use of differentiated mass flow. In Fluent k-ω SST and VLES turbulence models have been used and also two different numerical schemes in order to investigate their influence on the results. The results show that forces calculated with RELAP5 and Fluent are in parity. Small differences in mass flow and pressure appear when comparing between the codes. This probably stem from different handling of losses in RELAP5 and Fluent. The differences have no effect on forces calculated since the differentiated mass flow and pressure difference used are equivalent for both codes. / Vid Forsmarks Kraftgrupp AB (FKA) beräknas ofta krafter i rörsystem uppkomna av transienta flöden som ett steg i att verifiera systemens strukturella integritet. Inom kärnkraftsindustrin används vanligen det endimensionella termohydrauliska analysprogrammet RELAP5 vid utförande av transienta rörflödesberäkningar. Vid beräkningar med en mer komplex geometri använder FKA bl a det tredimensionella programmet Fluent. Detta program är generellt tidskrävande samt ställer stora krav på datorkapacitet. Målet med projeketet är att jämföra beräkningar av tryck, flöden och krafter, utförda med RELAP5 och Fluent, på en godtycklig rörsektion under transienta flödesvillkor. Ett transient flöde i en enklare geometri har simulerats i både RELAP5 och Fluent. Krafter har beräknats med två olika metoder, dels med tryckskillnad över rörsektionen samt även med massflödesderivatan. I Fluent har turbulensen modellerats med k-ω SST och VLES,två olika numeriska scheman har även använts för undersökning av dess påverkan på resultaten. Resultaten visar att krafter som beräknats med RELAP5 och Fluent är i paritet med varandra. Generellt är det små skillnader vid jämförelse av massflöde och tryck mellan programmen. Dessa bedöms härröra från olika behandling av förluster i RELAP5 och Fluent. Skillnaderna har ingen inverkan på de beräknade krafterna eftersom massflödesderivatan och tryckdifferensen som används är likvärdiga för båda programmen.

No description available.

This study investigates horizontal water turbine. Firstly, blade element momentum theory is exploited to design blade profiles. Then, CFD software, Fluent, is used to obtain such simulation results as torque, power and efficiency. A shroud outside the water turbine is tested to show the influence on the output power. Detailed parameters, shroud geometry and blade number, are considered too. Additionally, the maximal power generated by the turbine is analyzed under periodic sea current flow in this research. Our studies show that installed shroud can increase the output power more effectively and surely. Various kinds of shroud geometry have influence on the water turbine capability. As for the shroud types, nozzle type is better to achieve the best power. But as the inclined angle increases, the power also rises. The blade number boosts up the output power. Compared with other parameters, shroud length is of minor significance. On condition of periodic current flow, NACA63415 outperforms NACA0009, NACA0011 and Elliptical 10 in terms of airfoil, with its best efficiency and power.

No description available.

Purpose: The goal of this study was to develop a novel tool for connected speech analysis in aphasia, so that spoken output can be characterized in a data-driven and explanatory manner. Method: We designed a multidimensional rating scheme called the Auditory-Perceptual Rating of Connected Speech in Aphasia (APROCSA), in which 27 common features were each rated on a 5-point scale. Three researchers and twelve student clinicians rated 24 connected speech samples from the AphasiaBank database. Results: Ratings conducted by both researchers and student clinicians demonstrated good-to-excellent reliability and strong concurrent validity with AphasiaBank measures derived from transcriptions, clinical measures, and subscores from the Western Aphasia Battery (WAB). Factor analysis revealed that four underlying factors—Paraphasia, Logopenia, Agrammatism, and Motor speech—accounted for 79% of the variance in the connected speech profiles. Examination of individual patient scores showed considerable diversity of factor scores among patients of any given aphasia subtype. Conclusions: The APROCSA proved to be a reliable, valid, and efficient tool for research or clinical purposes. The preliminary findings of the factor analysis suggest a parcellation of non-fluency into three distinct profiles—Logopenia, Agrammatism, and Motor speech—which may occur in conjunction with other non-fluent profiles or with the fluent profile

Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2009

Accurate models and realistic simulations are essential in developing cleaner and more efficient coal- and biomass-fired boilers. Using the CFD simulation software Fluent The University of Iowa created a model of an industrial boiler that adequately compares the practice of co-firing biomass and coal against firing only coal. The simulations used in this comparison, show significant circulation zones and an unrealistic temperature profile inside the boiler heat exchanger region. This model is effective for comparing the relative decrease in emissions when co-firing with biomass versus exclusively coal combustion, but it does not present a realistic simulation of biomass or coal combustion. The purpose of the current work is to develop a more realistic baseline coal combustion model. Calculations for the proximate and ultimate analysis of coal, as well as properties necessary for energy and mass flux computations, have been updated in the current model. The fuel bed model - a simple two-dimensional distribution of energy and mass fluxes from the grate - was kept the same due to the complexities of fuel bed modeling. Simulation boundary conditions and flow models were tested and modified to determine the most realistic model settings. The geometry and mesh grid of the boiler model were also varied in an attempt to fix problematic areas. Several approaches were implemented in an effort to reduce the circulation zones and generate a realistic temperature profile. The negative energy source term in the boiler representing the energy removed by the water pipes in the heat exchanger was analyzed, and different configurations of this sink were tested. Finally, the heat exchanger models built in to Fluent were studied and implemented. These models proved to be the most effective in reducing recirculation zones and decreasing high temperature gradients. While the current model of the coal-fired boiler has a higher overall temperature than the previous one, circulation zones are almost completely eliminated, the flow path has been improved, and the temperature profile in the boiler is more realistic.