According to previous studies, a higher degree of processing fluency leads to higher liking; however, other studies indicate that a higher degree of processing fluency leads to lower recognition. This experiment examines the influence of processing fluency on both liking and recognition to determine if the same results occur when participants are asked to rate liking and remember images. Subjects rated a series of images by level of liking, then were given a recognition test. The stimuli were a combination of fluent and disfluent product images with varied fluency in each of four categories: Amount of Information, Figure-Ground Contrast, Clarity, and Symmetry. Results indicated that participants liked fluent images more than disfluent images. However, results also revealed a trend that recognition may have been higher for fluent images, and that the effects of fluency on recognition depended on which type was manipulated. Thus, the effects of varying processing fluency are different when participants are asked to both rate liking and remember items. This experiment aims to provide successful marketing tactics, suggesting that marketers make their products fluent in order to produce greater liking and memory.

Les systèmes piles à combustible sont intégrés dans un ensemble d'auxiliaires qui présentent des contraintes au fonctionnement de ceux-ci. Afin d'envisager un bon fonctionnement, il faut arriver à mieux contrôler ces auxiliaires en éliminant le maximum possible ces contraintes. La modélisation est de plus en plus envisagée pour y apporter une réponse. parmi ces différents types de modélisations, il y a celle qui consiste à traiter le problème de la gestion de l'eau, principale cause de noyage de sites réactionnels ds électrodes de piles. Une telle approche ne peut se faire sans difficulté car elle nécessite le couplage de plusieurs équations. Par utilisation d'un code CFD FLUENT, nous abordons dans une configuration réelle un type de modèle pouvant nous permettre d'apporter une réponse au problème posé par l'état hybride de la cellule. Cela consiste en la détermination de certains paramètres de transfert au coeur de la pile comme la température de la cellule, l'humidité relative, les pressions partielles ainsi que les débits molaires des constituants.

<p>Abstract</p><p>This thesis is studying the heatsinks new designs for copper heatsinks which utilizes modelling and simulation by CFD, construction of prototypes and experimental works. Challenges and complications in manufacturing of copper heatsinks are expressed and finding the solutions to these hindrances involve in this work. Numerical efforts supported by fluent are made to promote investigation and approaching the goal in which serves the new opportunities for wider application of copper material in heat sinks.</p><p>However the thermal conductivity of copper is about double as aluminium but still aluminium heatsinks are commonly used for heat dissipation in computers.</p><p>Comparing of heat performance of two analogous heatsink of different materials, aluminium and copper, is conducted by numerical analysis in the CFD environment.</p><p>In addition to larger surface area and airflow velocity another solution for enhancement of heat dissipation is suggested.</p><p>Manufacturing solutions of copper heatsinks are proposed which will facilitate fabrication of more high performance copper heatsinks than the current heavy and expensive models.</p><p>Our first copper heat sink model is designed exclusively based on the technical observations and analyses of numerical simulation of two identical copper and aluminium heatsinks by CFD and as well as manufacturability concerns.</p><p>This heat sink is fabricated mechanically and is tested by a number of heat sources and high sensitive devices such as adhesive K type thermocouple, data acquisition 34970A in associated with HP Bench Link program.</p><p>An extent experimental work on aluminium heatsinks, integrated with forced convection, is performed in order to measure their thermal capacities.</p><p>Comparison of the heat performance of a typical aluminium heatsink, which was the best among the all aluminium heat sinks and proposed copper heatsink under identical experimental conditions, is performed.</p><p>Also in some numerical efforts, optimizing and predicting of the thermal characterization of the proposed heatsink with inclined free fins is developed. The model is scaled up in the fluent environment to predict its application in the cooling of larger heat generated electronic devices.</p><p>Impingement air-cooling mode of force-convection is adopted for heat dissipation from high power electronic devices in associated with the proposed inclined fin model.</p><p>Components of airflow velocity in the hollow spaces of the heatsink are discussed. Pressure drop and other thermal variables are analyzed analytical and by CFD code.</p><p>Another mechanical manufactured copper heat sink is investigated. A new design of the base and fins is optimized.</p><p>A three-dimensional finite volume method is developed to determine the performance of the proposed heatsink.</p><p>Thermal and hydraulic characterization of the heat sink under air-forced convection cooling condition is studied. The flow behavior around the fins and some other parts of the heat sink is analyzed by utilizing CFD code.</p><p>The hydraulic parameters including velocity profiles, distribution of static pressure, dynamic pressure, boundary layer and fluid temperature between the fins and in the passageway at the middle of the heat sink are analyzed and presented schematically.</p><p>Furthermore the thermal characteristic of the proposed heatsink is studied by contouring the three dimensional temperature distributions through the fins and temperature of the heat source by CFD code.</p>

The airflow field and particle trajectories inside hard disk drive (HDD) are investigated in this study using commercial software Fluent and Gambit. Three-dimensional grids inside the HDD configuration are built using Gambit taking into account all the components and their geometric details. The airflow field inside HDD is simulated using three incompressible Navier-Stokes equations for various disk rotational speeds. The effects of using the various turbulence models inside the Fluent software such as the standard k - ε , RNG k - ε and Reynolds Stress Method on the computed airflow characteristics are also assessed. Steady flow fields and the effects of rotational speeds are assessed. Based on the computed steady airflow patterns, particle trajectories are computed using routines available in Fluent as well as special particle trajectory functions defined by the user via the user-defined functions. Particles of different sizes and materials are injected at various locations in the computed flow field and the corresponding particle trajectories are studied. Based on the investigation, the trajectory tends to be different according to sizes and materials. The present work forms a basis for further investigation of heat transfer processes inside the HDD to address thermal management issues and also the computation of unsteady flow fields in the HDD due to the movement of the actuator arm during data storage and retrieval / Singapore-MIT Alliance (SMA)

Abstract This thesis is studying the heatsinks new designs for copper heatsinks which utilizes modelling and simulation by CFD, construction of prototypes and experimental works. Challenges and complications in manufacturing of copper heatsinks are expressed and finding the solutions to these hindrances involve in this work. Numerical efforts supported by fluent are made to promote investigation and approaching the goal in which serves the new opportunities for wider application of copper material in heat sinks. However the thermal conductivity of copper is about double as aluminium but still aluminium heatsinks are commonly used for heat dissipation in computers. Comparing of heat performance of two analogous heatsink of different materials, aluminium and copper, is conducted by numerical analysis in the CFD environment. In addition to larger surface area and airflow velocity another solution for enhancement of heat dissipation is suggested. Manufacturing solutions of copper heatsinks are proposed which will facilitate fabrication of more high performance copper heatsinks than the current heavy and expensive models. Our first copper heat sink model is designed exclusively based on the technical observations and analyses of numerical simulation of two identical copper and aluminium heatsinks by CFD and as well as manufacturability concerns. This heat sink is fabricated mechanically and is tested by a number of heat sources and high sensitive devices such as adhesive K type thermocouple, data acquisition 34970A in associated with HP Bench Link program. An extent experimental work on aluminium heatsinks, integrated with forced convection, is performed in order to measure their thermal capacities. Comparison of the heat performance of a typical aluminium heatsink, which was the best among the all aluminium heat sinks and proposed copper heatsink under identical experimental conditions, is performed. Also in some numerical efforts, optimizing and predicting of the thermal characterization of the proposed heatsink with inclined free fins is developed. The model is scaled up in the fluent environment to predict its application in the cooling of larger heat generated electronic devices. Impingement air-cooling mode of force-convection is adopted for heat dissipation from high power electronic devices in associated with the proposed inclined fin model. Components of airflow velocity in the hollow spaces of the heatsink are discussed. Pressure drop and other thermal variables are analyzed analytical and by CFD code. Another mechanical manufactured copper heat sink is investigated. A new design of the base and fins is optimized. A three-dimensional finite volume method is developed to determine the performance of the proposed heatsink. Thermal and hydraulic characterization of the heat sink under air-forced convection cooling condition is studied. The flow behavior around the fins and some other parts of the heat sink is analyzed by utilizing CFD code. The hydraulic parameters including velocity profiles, distribution of static pressure, dynamic pressure, boundary layer and fluid temperature between the fins and in the passageway at the middle of the heat sink are analyzed and presented schematically. Furthermore the thermal characteristic of the proposed heatsink is studied by contouring the three dimensional temperature distributions through the fins and temperature of the heat source by CFD code.

The ability of a propulsion system is very crucial for the capability of a missile or a rocket system. Unlike liquid propellant rocket motors, the only control mechanism of the thrust value is the propellant geometry in solid propellant rocket motors. When the operation of solid propellant rocket motor has started, it cannot be stopped anymore. For this main reason the advance of dual pulse motor technology has started. The aim of this study is to investigate the geometrical effects of design parameters on the flow behavior of a dual pulse solid propellant rocket motor by using commercial Computational Fluid Dynamics (CFD) methods. For the CFD analysis, a generic dual pulse rocket motor model is constituted. Within this model, initially four different geometry alternatives of Pulse Separation Device (PSD) are analyzed. To begin PSD analyses, mesh sensitivity analyses are performed on one PSD geometry alternative. By defined grid size, the analyses of PSD geometry alternatives are performed. Computed results were compared in terms of flow behavior (flow streamlines, velocity distribution, turbulent kinetic energy&hellip / etc.) with each other. With the selected PSD geometry alternative the effects of L/D ratio (Length/Diameter ratio) of first pulse chamber, Achamb/APSD ratio (Chamber area/PSD opening area) and APSD/Ath ratio (PSD opening area/Throat area) on the flow behavior is investigated. Flow analyses are performed by simulating the unsteady flow of second pulse operation. With the performed analyses, it is aimed to identify generic geometric definitions for a dual pulse rocket motor.

Thermoelectric devices are capable of providing both localized active cooling and waste heat power generation. This work will explore the possibility of embedding thermoelectric devices within electronic packaging in order to achieve better system performance. Intel and Nextreme, Inc. have produced thin-film superlattice thermoelectric devices that have above average performance for thermoelectrics and are much thinner than most devices on the market currently. This allows them to be packaged inside of the electronic package where the thermoelectric devices can take advantage of the increased temperatures and decreased thermal lag as compared to the devices being planted on the outside of the package. This work uses the numerical CFD solver FLUENT and the analog electronic circuit simulator SPICE to simulate activity of thermoelectric devices within an electronics package.

A spur dike is a hydraulic structure built on the bank of a river at some angle to the main flow direction. A series of spur dikes in a row may also be placed on one side or both sides of a river to form a spur dike field. Spur dikes are used for two main purposes, namely river training and bank protection. For river training, spur dikes may be used to provide a desirable path for navigation purposes or to direct the flow to a desirable point such as a water intake. For bank protection, spur dikes may be used to deflect flow away from a riverbank and thus protect it from erosion. It has also been observed that spur dikes provide a desirable environment for aquatic habitat. Despite the fact that spur dikes are useful hydraulic structures, they have been found to increase the flow resistance in rivers and hence increase the flow stage. The present study focuses on the quantification of the flow resistance and associated flow stage increase due to a single spur dike and also that of a spur dike field. Increased flow stage is referred to herein as a backwater effect.<p> In the first stage of the study, the flow resistance due to a single spur dike, expressed as a drag force exerted on the flow in an open channel, was studied and quantified. The work was carried out in a rigid bed flume, with the model spur dike being simulated using various sizes of a two-dimensional (2-D) rectangular plate. Several discharge conditions were studied. The drag force exerted by the spur dike for both submerged and unsubmerged flow conditions was determined directly from measurements made using a specially designed apparatus and also by application of the momentum equation to a control volume that included the spur dike. It was found that the unit drag force (i.e., drag force per unit area of dike) of an unsubmerged spur dike increases more rapidly with an increase in the discharge when compared with that of a submerged spur dike. The results also showed that an increase in the blockage of the open channel cross-section due to the spur dike is the main parameter responsible for an increase in the spur dike drag coefficient, hence the associated flow resistance and backwater effect. Based on these findings, relationships were developed for estimating the backwater effect due to a single spur dike in an open channel.<p> In the second stage of the study, the flow resistance due to a spur dike field expressed as a drag force exerted on the flow was quantified and subsequently related to the backwater effect. The work was carried out in a rigid bed flume, with the model spur dikes simulated using 2-D, rectangular plates placed along one side of the flume. For various discharges, the drag force of each individual spur dike in the spur dike field was measured directly using a specially-designed apparatus. For these tests, both submerged and unsubmerged conditions were evaluated along with various numbers of spur dikes and various relative spacings between the spur dikes throughout the field. It was concluded that the configuration of a spur dike field in terms of the number of spur dikes and relative spacing between the spur dikes has a substantial impact on the drag force and hence the flow resistance and backwater effect of a spur dike field. The most upstream spur dike had the highest drag force amongst the spur dikes in the field, and it acted as a shield to decrease the drag force exerted by the downstream spur dikes. From the experiments on the submerged spur dikes, it was observed that the jet flow over the spur dikes has an important effect on the flow structure and hence the flow resistance.<p> In the third stage of the study, the flow field within the vicinity of a single submerged spur dike was modeled using the three-dimensional (3-D) computational fluid dynamic (CFD) software FLUENT. Application of the software required solution of the 3-D Reynolds-averaged Navier-Stokes equations wherein the Reynolds stresses were resolved using the RNG ê-å turbulence model. One discharge condition was evaluated in a smooth, rectangular channel for two conditions, including uniform flow conditions without the spur dike in place and one with the spur dike in place. The CFD model was evaluated based on some experimental data acquired from the physical model. It was found that the CFD model could satisfactorily predict the flow resistance and water surface profile adjacent to the spur dike, including the resulting backwater effect. Furthermore, the CFD model gave a good prediction of the velocity field except for the area behind the spur dike where the effects of diving jet flow over the spur dike was not properly modeled.

A spur dike is a hydraulic structure built on the bank of a river at some angle to the main flow direction. A series of spur dikes in a row may also be placed on one side or both sides of a river to form a spur dike field. Spur dikes are used for two main purposes, namely river training and bank protection. For river training, spur dikes may be used to provide a desirable path for navigation purposes or to direct the flow to a desirable point such as a water intake. For bank protection, spur dikes may be used to deflect flow away from a riverbank and thus protect it from erosion. It has also been observed that spur dikes provide a desirable environment for aquatic habitat. Despite the fact that spur dikes are useful hydraulic structures, they have been found to increase the flow resistance in rivers and hence increase the flow stage. The present study focuses on the quantification of the flow resistance and associated flow stage increase due to a single spur dike and also that of a spur dike field. Increased flow stage is referred to herein as a backwater effect.<p> In the first stage of the study, the flow resistance due to a single spur dike, expressed as a drag force exerted on the flow in an open channel, was studied and quantified. The work was carried out in a rigid bed flume, with the model spur dike being simulated using various sizes of a two-dimensional (2-D) rectangular plate. Several discharge conditions were studied. The drag force exerted by the spur dike for both submerged and unsubmerged flow conditions was determined directly from measurements made using a specially designed apparatus and also by application of the momentum equation to a control volume that included the spur dike. It was found that the unit drag force (i.e., drag force per unit area of dike) of an unsubmerged spur dike increases more rapidly with an increase in the discharge when compared with that of a submerged spur dike. The results also showed that an increase in the blockage of the open channel cross-section due to the spur dike is the main parameter responsible for an increase in the spur dike drag coefficient, hence the associated flow resistance and backwater effect. Based on these findings, relationships were developed for estimating the backwater effect due to a single spur dike in an open channel.<p> In the second stage of the study, the flow resistance due to a spur dike field expressed as a drag force exerted on the flow was quantified and subsequently related to the backwater effect. The work was carried out in a rigid bed flume, with the model spur dikes simulated using 2-D, rectangular plates placed along one side of the flume. For various discharges, the drag force of each individual spur dike in the spur dike field was measured directly using a specially-designed apparatus. For these tests, both submerged and unsubmerged conditions were evaluated along with various numbers of spur dikes and various relative spacings between the spur dikes throughout the field. It was concluded that the configuration of a spur dike field in terms of the number of spur dikes and relative spacing between the spur dikes has a substantial impact on the drag force and hence the flow resistance and backwater effect of a spur dike field. The most upstream spur dike had the highest drag force amongst the spur dikes in the field, and it acted as a shield to decrease the drag force exerted by the downstream spur dikes. From the experiments on the submerged spur dikes, it was observed that the jet flow over the spur dikes has an important effect on the flow structure and hence the flow resistance.<p> In the third stage of the study, the flow field within the vicinity of a single submerged spur dike was modeled using the three-dimensional (3-D) computational fluid dynamic (CFD) software FLUENT. Application of the software required solution of the 3-D Reynolds-averaged Navier-Stokes equations wherein the Reynolds stresses were resolved using the RNG ê-å turbulence model. One discharge condition was evaluated in a smooth, rectangular channel for two conditions, including uniform flow conditions without the spur dike in place and one with the spur dike in place. The CFD model was evaluated based on some experimental data acquired from the physical model. It was found that the CFD model could satisfactorily predict the flow resistance and water surface profile adjacent to the spur dike, including the resulting backwater effect. Furthermore, the CFD model gave a good prediction of the velocity field except for the area behind the spur dike where the effects of diving jet flow over the spur dike was not properly modeled.

The present work seeks to investigate the thermal hydraulic (heat transfer and fluid dynamics) behavior of supercritical (Sc) fluids at both the fundamental and applied levels. The thermal hydraulics of these fluids is not very well known although they have been used in various applications. There are drastic changes in the thermal and hydraulic properties of fluids at supercritical conditions. There has been a lot of focus to effectively utilize these properties changes in many applications such as heat exchangers. This work focuses on studying the forced convective heat transfer of Sc-CO2 in a series of mini semi-circular horizontal tubes and a zig-zag shaped horizontal channel. The problems were investigated numerically by second-order finite volume method using a commercial software FLUENT. Three dimensional Computational Fluid Dynamics (CFD) models were developed to simulate the flow and heat transfer for three different geometries – a single semi-circular channel, a series of nine parallel semi-circular channels and a zig-zag channel. Grid and accuracy refinement studies were carried out to assess numerical errors. All the computational meshes developed for this study incorporated the first node cell within the viscous sub-layer i.e. y <1. Since the flow is turbulent, an appropriate choice of turbulence model is highly desirable. Henceforth, various turbulence models were used to study their impact on the heat transfer solution for these problems. The present numerical work focuses on improving the CFD model and methodologies in order to capture the experimental data of the heat transfer spike at the super critical conditions. Local and average heat transfer coefficients near the critical point were determined from measured wall temperatures and calculated local bulk temperatures. The numerical results are compared with the experiments. The numerical predictions do not convincingly agree with the experiments. This could be because of the incapability of turbulent models to capture the flow physics accurately due to the rapid changes in the fluid properties near critical conditions.