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Full-Text Articles in Mechanical Engineering

Assessment And Improvement Of Computational Fluid Dynamics Methods For Separated Turbulent Flows At Low Reynolds Numbers, Tom Mancuso Jan 2020

Assessment And Improvement Of Computational Fluid Dynamics Methods For Separated Turbulent Flows At Low Reynolds Numbers, Tom Mancuso

Dissertations, Master's Theses and Master's Reports

This study investigates the accuracy of Computational Fluid Dynamics (CFD) models to predict heat transfer in turbulent separated flows at low Reynolds numbers. A novel improvement of a Scale Adaptive technique is also presented. A spectrum of turbulence models is used to simulate flow and heat transfer of two geometries; fully developed flow through a staggered tube bank and a square prism in cross flow. Experimental data for both local heat transfer and velocity data are available in the literature for these cases and have been used extensively evaluate various CFD methods. Six unsteady models were used and the results ...


Efficient Enhancement Of Micro-Nucleation Rates In Flow-Boiling - By Concurrent Micro-Structuring Of The Boiling-Surface And Its Judicious Energization By Piezoelectric-Transducer Induced Acoustic Vibrations., Atharva Rahane Jan 2020

Efficient Enhancement Of Micro-Nucleation Rates In Flow-Boiling - By Concurrent Micro-Structuring Of The Boiling-Surface And Its Judicious Energization By Piezoelectric-Transducer Induced Acoustic Vibrations., Atharva Rahane

Dissertations, Master's Theses and Master's Reports

The report describes the science and technology backgrounds and uses for the technology breakthrough reported for enhanced flow-boiling based cooling of high-power density electronics (chips, memory etc.). A controlled but explosive growth in micro-scale nucleation rates during flow-boiling of HFE-7100 (electronics and environment friendly liquid from 3M, Inc) is enabled by the uses of inexpensive meshed-copper for micro-structuring of the boiling surface and a pair of Piezoelectric-transducers for active imposition of suitable acoustic vibrations. The pair of piezo transducers mounted just outside the mini-channel impose “in plane” acoustic vibrations of controllable amplitudes and frequencies, and they are used to induce ...


Networked Microgrid Optimization And Energy Management, Robert S. Jane Jan 2019

Networked Microgrid Optimization And Energy Management, Robert S. Jane

Dissertations, Master's Theses and Master's Reports

Military vehicles possess attributes consistent with a microgrid, containing electrical energy generation, storage, government furnished equipment (GFE), and the ability to share these capabilities via interconnection. Many military vehicles have significant energy storage capacity to satisfy silent watch requirements, making them particularly well-suited to share their energy storage capabilities with stationary microgrids for more efficient energy management. Further, the energy generation capacity and the fuel consumption rate of the vehicles are comparable to standard diesel generators, for certain scenarios, the use of the vehicles could result in more efficient operation. Energy management of a microgrid is an open area of ...


Influence Of Micro-Nucleate Boiling On Annular Flow Regime Heat Transfer Coefficient Values And Flow Parameters – For High Heat-Flux Flow Boiling Of Water, Soroush Sepahyar Jan 2019

Influence Of Micro-Nucleate Boiling On Annular Flow Regime Heat Transfer Coefficient Values And Flow Parameters – For High Heat-Flux Flow Boiling Of Water, Soroush Sepahyar

Dissertations, Master's Theses and Master's Reports

Analysis of results from steady and steady-in-the-mean high heat-flux (15 - 70 W/cm2, with water as working fluid) shear driven annular flow-boiling experiments presented here - and low heat-flux (0.1- 1 W/cm2, with FC-72 as working fluid) experiments presented elsewhere – together lead to a key conclusion. The conclusion is that heat carrying nucleation rates go often undetected by the typically used visualization approaches for flow boiling – as such flows often involve µm- to sub- µm scale bubble diameters in millimeter-scale ducts. These nucleation rates play a significant role in most of the so-called convective annular regimes (of ...


Paddle Mixer-Extrusion Reactor For Torrefaction And Pyrolysis, Stas Zinchik Jan 2019

Paddle Mixer-Extrusion Reactor For Torrefaction And Pyrolysis, Stas Zinchik

Dissertations, Master's Theses and Master's Reports

This work is focused on the fundamental understanding and the development of paddle mixer reactors (or modified screw augers). This work will contribute to the effort of the thermal conversion of biomass and wastes. We developed and studied two paddle systems (i) 25-mm lab-scale (up to 1 kg/hr) and (ii) 101-mm pilot-scale (up to 100 kg/hr). Thermal behavior of the two systems was studied and it was estimated that the lab-scale system has a high heating rate of up to 530 °C/s. Residence times were thoroughly measured and were determined as a function of rotation frequency and ...


High Injection Pressure Dme Ignition And Combustion Processes: Experiment And Simulation, Xiucheng Zhu Jan 2019

High Injection Pressure Dme Ignition And Combustion Processes: Experiment And Simulation, Xiucheng Zhu

Dissertations, Master's Theses and Master's Reports

With nearly smokeless combustion, Dimethyl Ether (DME) can be pressurized and used as a liquid fuel for compression-ignition (CI) combustion. However, due to its lower heating value and liquid density compared with diesel fuel, DME has a smaller energy content per unit volume. To obtain an equivalent energy content of diesel, approximately 1.86 times more quantity of DME is required. This can be addressed by a larger nozzle size or higher injection pressure. However, the effect of high injection pressure on DME spray combustion characteristics have not yet been well understood. In order to fill this gap, spray and ...


Multi-Scale, Capillary Assisted Copper Surfaces For Enhanced Pool Boiling Heat Transfer Processes, Chetan Agarwal Jan 2019

Multi-Scale, Capillary Assisted Copper Surfaces For Enhanced Pool Boiling Heat Transfer Processes, Chetan Agarwal

Dissertations, Master's Theses and Master's Reports

Phase-change heat transfer through pool boiling process offers a promising thermal management solution in applications wherein conventional air or single-phase liquid-based cooling methods prove inefficient such as for high-power electronics. Pool boiling process, which utilizes the latent heat of evaporation, provides a robust and efficient way to efficiently dissipate the excessive heat generated in a small footprint area in particular as seen in CPUs (Central Processing Units), GPUs (Graphics Processing Units), LEDs (Light Emitting Diodes), radars, and other demanding computing, sensing and surveillance electronics. Although boiling process has been studied for over five decades, it has not been yet adapted ...


Modeling And Control Of Maximum Pressure Rise Rate In Rcci Engines, Aditya Basina Jan 2019

Modeling And Control Of Maximum Pressure Rise Rate In Rcci Engines, Aditya Basina

Dissertations, Master's Theses and Master's Reports

Low Temperature Combustion (LTC) is a combustion strategy that burns fuel at lower temperatures and leaner mixtures in order to achieve high efficiency and near zero NOx emissions. Since the combustion happens at lower temperatures it inhibits the formation of NOx and soot emissions. One such strategy is Reactivity Controlled Compression Ignition (RCCI). One characteristic of RCCI combustion and LTC com- bustion in general is short burn durations which leads to high Pressure Rise Rates (PRR). This limits the operation of these engines to lower loads as at high loads, the Maximum Pressure Rise Rate (MPRR) hinders the use of ...


Development Of A 2d Scr Catalyst On A Diesel Particulate Filter Model For Design And Control Applications To A Ultra Low Nox Aftertreatment System, Venkata Chundru Jan 2019

Development Of A 2d Scr Catalyst On A Diesel Particulate Filter Model For Design And Control Applications To A Ultra Low Nox Aftertreatment System, Venkata Chundru

Dissertations, Master's Theses and Master's Reports

This research focuses on modeling and control of PM and NOx in diesel engine exhaust using an SCR catalyst on a Diesel Particulate Filter (SCR-F). A 2D SCR-F model was developed that is capable of predicting internal states: 2D temperature, PM and NH3storage distributions and filtration efficiency, pressure drop, PM mass retained in the PM cake and substrate wall and outlet NO, NO2and NH3concentrations. The SCR-F model was used to simulate a DOC + SCR-F + DOC + SCR ultra-low NOx system that can achieve > 99.5% NOx conversion efficiency.

The model was calibrated with experimental ...


Capillary-Assisted Enhanced Condensation Heat Transfer For Low Surface Tension Liquids, Gnana Vishnu Durgam Jan 2018

Capillary-Assisted Enhanced Condensation Heat Transfer For Low Surface Tension Liquids, Gnana Vishnu Durgam

Dissertations, Master's Theses and Master's Reports

Extensive research has been carried out over the course of the last few decades to induce dropwise condensation as it offers 5 - 7 times better heat transfer performance compared to filmwise condensation process. A number of methods such as low surface energy hydrophobic coatings, surface modification of hydrophobic surfaces to fabricate micro, nano and hierarchical structures, and the recent incorporation of jumping droplet phenomenon have provided effective means to further enhance the condensation heat transfer. However, existing methods to enhance condensation heat transfer rate fail in the case of low surface tension, highly wetting liquids such as hydrocarbons, cryogens, and ...


Spray And Combustion Studies Of High Reactivity Gasoline In Comparison To Diesel Under Advanced Compression Ignition Engine Conditions, Meng Tang Jan 2018

Spray And Combustion Studies Of High Reactivity Gasoline In Comparison To Diesel Under Advanced Compression Ignition Engine Conditions, Meng Tang

Dissertations, Master's Theses and Master's Reports

Gasoline compression ignition (GCI) technology has demonstrated great potentials in improving fuel economy and reducing engine-out NOx and particulate matter emissions. Development and application of the GCI technology on multi-cylinder engines require both fundamental understandings of the gasoline spray combustion characteristics and accurate numerical tools. Due to the large differences in the thermo-physical and the chemical properties between gasoline and diesel range fuels, differences in the spray combustion characteristics between gasoline and diesel is expected. Reports on the gasoline spray combustion characteristics under conditions relevant to medium to heavy-duty engines are scarce and this dissertation aims to fill in ...


Thermomagnetic Convective Cooling Of Hall Effect Thruster, Elizabeth M. Vanheusden Jan 2018

Thermomagnetic Convective Cooling Of Hall Effect Thruster, Elizabeth M. Vanheusden

Dissertations, Master's Theses and Master's Reports

This work proposes and shows that thermomagnetic convection could be used in zero gravity to cool components of a Hall-effect thruster. A ferrofluid cavity was develop in the thermal and geometric model of a Hall-effect thruster. Simulations show that with an Ionic Liquid Ferrofluid after two minutes of thruster operations thermomagnetic convection occurs and in zero gravity will produce a larger velocity then natural convection that occurs in earth gravity. However, experiments did not result in heat transfer enhancement due to the limitation of the ferrofluid. Replacement of the Ferrotec EFH1 dispersant with dodecylbenzene did not result in Ionic Liquid ...


Investigation On The Potential Of A Co2 Capture System, Downstream Of The Aftertreatment System For A Heavy-Duty Engine Application, Murchana Pathak Jan 2018

Investigation On The Potential Of A Co2 Capture System, Downstream Of The Aftertreatment System For A Heavy-Duty Engine Application, Murchana Pathak

Dissertations, Master's Theses and Master's Reports

The transportation sector accounts for the second largest source of CO2 emissions after power generation. New Corporate Average Fuel Economy (CAFE) regulations are focusing on improving energy through reduced fuel consumption and greenhouse gas emissions. This work investigates the potential of a CO2 capture system downstream of an aftertreatment system for a heavy-duty engine application. Amine absorption has been described as one of the most effective ways to capture CO2 from the exhaust for point sources. Therefore, using thermal-swing absorption process with potassium carbonate (K2CO3) as the absorbent liquid, a process was analyzed for ...


An Experimental And Computational Study Of Fuel Spray Interaction: Fundamentals And Engine Applications, Le Zhao Jan 2018

An Experimental And Computational Study Of Fuel Spray Interaction: Fundamentals And Engine Applications, Le Zhao

Dissertations, Master's Theses and Master's Reports

An efficient spray injection results in better vaporization and air-fuel mixing, leading to combustion stability and reduction of emissions in the internal combustion (IC) engines. The impingement of liquid fuels on chamber wall or piston surface in IC engines is a common phenomenon and fuel film formed in the spray-piston or cylinder wall impingement plays a critical role in engine performance and emissions. Therefore, the study of the spray impingement on the chamber wall or position surface is necessary.

To understand the spray-wall interaction, a single droplet impingement on a solid surface with different conditions was first examined. The droplet-wall ...


A New Technique To Determine Accommodation Coefficients Of Cryogenic Propellants, Kishan Bellur Jan 2018

A New Technique To Determine Accommodation Coefficients Of Cryogenic Propellants, Kishan Bellur

Dissertations, Master's Theses and Master's Reports

The control of propellant boil-off is essential in long-term space missions. However, a clear understanding of cryogenic propellant phase change and the values of accommodation coefficients are lacking. To that effect, a new method to determine accommodation coefficients using a combination of neutron imaging, thin film evaporation modeling and CFD modeling has been established. Phase change experiments were conducted in the BT-2 Neutron Imaging Facility at the National Institute of Standards and Technology (NIST) by introducing cryogenic vapor (H2 and CH4) at a set pressure into Al6061 and SS316L test cells placed inside a 70mm cryostat. Condensation is achieved by ...


Analysis Of Injection Parameters Influencing Gasoline Direct Injection Compression Ignition (Gdici) Engine Operation In Ltc Using Naphtha, Devyani Patil Jan 2018

Analysis Of Injection Parameters Influencing Gasoline Direct Injection Compression Ignition (Gdici) Engine Operation In Ltc Using Naphtha, Devyani Patil

Dissertations, Master's Theses and Master's Reports

A multi-dimensional CFD study using MTU-KIVA-Geq-CHEMKIN code has been carried out for direct injection compression ignition engine combustion fueled with heavy naphtha, light naphtha, and PRF50 in low-temperature combustion (LTC) regime. At constant fueling, combustion characteristics are investigated as a function of injection timing and injection pressure. Further, operating limits of fuel confined by combustion efficiency, noise level (Maximum Pressure rise rate) and emissions at exhaust valve opening (EVO) are evaluated using parametric variation of initial gas temperature, exhaust gas recirculation fraction, boost pressure. Research conducted focuses on ability of fuel to get good combustion which is combustion efficiency > / = 90 ...


Pyrolysis Of Fiber-Plastic Waste Blends, Shreyas Kolapkar Jan 2018

Pyrolysis Of Fiber-Plastic Waste Blends, Shreyas Kolapkar

Dissertations, Master's Theses and Master's Reports

The main objective of this work is to investigate fast pyrolysis of fiber and plastic feedstocks in order to understand the synergistic effect from their co-pyrolysis. In this on-going work, fiber, plastic and their blend are characterized and pyrolysis oil is produced from them in the fast batch pyrolysis reactor. Based on a heat transfer model it is shown that results of oil produced from batch reactor will be applicable to the continuous paddle reactor. From feedstock characterization, chlorine was observed particularly in the plastic feedstock. Thus, chlorine removal method using torrefaction and high shear mixing was implemented and was ...


Experimental Investigation Of Impinged Droplet Dynamics, Nitisha Ahuja Jan 2018

Experimental Investigation Of Impinged Droplet Dynamics, Nitisha Ahuja

Dissertations, Master's Theses and Master's Reports

The fuel spray wall interaction phenomenon plays an essential role in determining the emissions and performance of an internal combustion engine. The investigation of single droplet wall interaction is crucial to understanding of a spray wall impingement process. This report is a compilation of the experimental work done to understand the droplet impingement characteristics, through optical diagnostics and temperature measurement. Different fuels and different surface under ambient and elevated temperature conditions are used for these tests, with two objectives: Development of a common depositionsplashing criteria; and Understanding droplet post impingement dynamics variation with factors like: Weber number (ratio of inertia ...


Experimental And Computational Investigation Of Dual Fuel Diesel- Natural Gas Rcci Combustion In A Heavy-Duty Diesel Engine, Mufaddel Dahodwala Jan 2018

Experimental And Computational Investigation Of Dual Fuel Diesel- Natural Gas Rcci Combustion In A Heavy-Duty Diesel Engine, Mufaddel Dahodwala

Dissertations, Master's Theses and Master's Reports

Among the various alternative fuels, natural gas is considered as a leading candidate for heavy-duty applications due to its availability and applicability in conventional internal combustion diesel engines. Compared to their diesel counterparts natural gas fueled spark-ignited engines have a lower power density, reduced low-end torque capability, limited altitude performance, and ammonia emissions downstream of the three-way catalyst. The dual fuel diesel/natural gas engine does not suffer with the performance limitations of the spark-ignited concept due to the flexibility of switching between different fueling modes. Considerable research has already been conducted to understand the combustion behavior of dual fuel ...


Experimental Investigations Of Temperature Controlled Innovative Annular Flow-Boiling Of Fc-72 In Millimeter Scale Ducts – Steady And Enhanced Pulsatile Realizations, Patcharapol Gorgitrattanagul Jan 2017

Experimental Investigations Of Temperature Controlled Innovative Annular Flow-Boiling Of Fc-72 In Millimeter Scale Ducts – Steady And Enhanced Pulsatile Realizations, Patcharapol Gorgitrattanagul

Dissertations, Master's Theses and Master's Reports

Steady and steady-in-the-mean shear driven annular flow-boiling is experimentally investigated in this thesis. By annular flow-regime one means separated liquid and vapor flows with the flowing liquid film staying on the boiling-surface.

The goals for the steady annular flow-boiling operations are to better understand relative importance of heat-transfer mechanisms (nucleation versus convective phase-change, with convective meaning absence of nucleation) and to develop better quantitative characterizations/correlations for heat-transfer rates. The goals for the steady-in-the-mean annular investigations was to explore improved means of significantly increasing heat transfer rates - while retaining the flow-regime's annularity.

The experimental investigations (with FC-72 as a ...


Development Of An Evaporation Sub-Model And Simulation Of Multiple Droplet Impingement In Volume Of Fluid Method, Sathya Prasad Potham Jan 2017

Development Of An Evaporation Sub-Model And Simulation Of Multiple Droplet Impingement In Volume Of Fluid Method, Sathya Prasad Potham

Dissertations, Master's Theses and Master's Reports

Droplet collision and impingement on a substrate are widely observed phenomenon in many applications like spray injection of Internal Combustion Engines. Existing Lagrangian models do not provide a comprehensive picture of the outcome of these events and may involve model constants requiring experimental data for validation. Physics based models like Volume of Fluid (VOF) method involve no parametric tuning and are more accurate. The aim of this thesis is to extend the basic VOF method with an evaporation sub-model including an additional vapor phase and implement this model in an open source Computational Fluid Dynamics (CFD) software, OpenFOAM. The new ...


Model-Based Control Of Hybrid Electric Powertrains Integrated With Low Temperature Combustion Engines, Ali Soloukmofrad Jan 2017

Model-Based Control Of Hybrid Electric Powertrains Integrated With Low Temperature Combustion Engines, Ali Soloukmofrad

Dissertations, Master's Theses and Master's Reports

Powertrain electrification including hybridizing advanced combustion engines is a viable cost-effective solution to improve fuel economy of vehicles. This will provide opportunity for narrow-range high-efficiency combustion regimes to be able to operate and consequently improve vehicle’s fuel conversion efficiency, compared to conventional hybrid electric vehicles (HEV)s. Low temperature combustion (LTC) engines offer the highest peak brake thermal efficiency reported in literature, but these engines have narrow operating range. In addition, LTC engines have ultra-low soot and nitrogen oxides (NOx) emissions, compared to conventional compression ignition and spark ignition (SI) engines. This dissertation concentrates on integrating the LTC engines ...


Modeling Mass And Thermal Transport In Thin Porous Media Of Pem Fuel Cells, Vinaykumar Konduru Jan 2017

Modeling Mass And Thermal Transport In Thin Porous Media Of Pem Fuel Cells, Vinaykumar Konduru

Dissertations, Master's Theses and Master's Reports

Water transport in the Porous Transport Layer (PTL) plays an important role in the efficient operation of polymer electrolyte membrane fuel cells (PEMFC). Excessive water content as well as dry operating conditions are unfavorable for efficient and reliable operation of the fuel cell. The effect of thermal conductivity and porosity on water management are investigated by simulating two-phase ow in the PTL of the fuel cell using a network model. In the model, the PTL consists of a pore-phase and a solid-phase. Different models of the PTLs are generated using independent Weibull distributions for the pore-phase and the solid-phase. The ...


Turbulent Transition Simulation And Particulate Capture Modeling With An Incompressible Lattice Boltzmann Method, John R. Murdock Jan 2017

Turbulent Transition Simulation And Particulate Capture Modeling With An Incompressible Lattice Boltzmann Method, John R. Murdock

Dissertations, Master's Theses and Master's Reports

Derivation of an unambiguous incompressible form of the lattice Boltzmann equation is pursued in this dissertation. Further, parallelized implementation in developing application areas is researched. In order to achieve a unique incompressible form which clarifies the algorithm implementation, appropriate ansatzes are utilized. Through the Chapman-Enskog expansion, the exact incompressible Navier-Stokes equations are recovered. In initial studies, fundamental 2D and 3D canonical simulations are used to evaluate the validity and application, and test the required boundary condition modifications. Several unique advantages over the standard equation and alternative forms found in literature are found, including faster convergence, greater stability, and higher fidelity ...


Assessment Of Annular Flow Boiling In The Context Of Computational Fluid Dynamics (Cfd) Simulations, Experiments, And Existing Correlations, Hrishikesh Prasad Ranga Prasad Jan 2017

Assessment Of Annular Flow Boiling In The Context Of Computational Fluid Dynamics (Cfd) Simulations, Experiments, And Existing Correlations, Hrishikesh Prasad Ranga Prasad

Dissertations, Master's Theses and Master's Reports

The main objective of the current work is to achieve a better understanding – through modeling and simulation/programming activities – of annular flow-boiling and its applications based on a synthesis of Computational Fluid Dynamics (CFD) simulations, existing correlations, and experiments. A unique and rigorous 2-D CFD simulations technique was developed for annular flow-boiling to propose a correlation for convective component of Heat Transfer Coefficient (HTC) – defined here as flow-boiling in the absence of nucleation. To provide a context for the correlation structure of convective component of HTC, flow-physics details of annular flow-boiling and correlation structure (based on fundamental considerations) for HTC ...


The Impact Of Water Injection On Spark Ignition Engine Performance Under High Load Operation, Jeremy Worm Jan 2017

The Impact Of Water Injection On Spark Ignition Engine Performance Under High Load Operation, Jeremy Worm

Dissertations, Master's Theses and Master's Reports

An experimental effort has been completed in which water injection was investigated as a means of enabling increases in engine output and high load efficiency. Water was injected into the intake port of a direct fuel injected, 4-cylinder, boosted engine with dual independent variable valve timing. The water was shown to increase volumetric efficiency and decrease the onset of knock which in turn enable more optimal combustion phasing. Both of these affects resulted increases in load of up to 5.5% at the same manifold pressure as the baseline case. The advancement of combustion phasing, combined with elimination of fuel ...


Utilizing Reprap Style 3d Printers For The Manufacturing Of Composite Heat Exchangers, John Laureto Jan 2017

Utilizing Reprap Style 3d Printers For The Manufacturing Of Composite Heat Exchangers, John Laureto

Dissertations, Master's Theses and Master's Reports

The low cost 3D printing market is currently dominated by the application of RepRap (self-replicating rapid-prototyper) variants. Presented in this document are practical utilizations of RepRap technology. Developed are innovative processes to manufacture composite materials systems for thermal management solutions.

First, a laser polymer welder system is validated by quantifying maximum peak load and weld width of linear low density polyethylene (LLDPE) lap welds as a function of linear energy density. The development of practical engineering data, in this application, is critical to producing mechanically durable welds. Developed laser and printer parameter sets allow for manufacturing of LLDPE multi-layered heat ...


Incorporation Of Higher Carbon Number Alcohols In Gasoline Blends For Application In Spark-Ignition Engines, Kristina Lawyer Jan 2017

Incorporation Of Higher Carbon Number Alcohols In Gasoline Blends For Application In Spark-Ignition Engines, Kristina Lawyer

Dissertations, Master's Theses and Master's Reports

The 2007 U.S. Renewable Fuel Standard (RFS2) requires an increase in the use of advanced biofuels up to 36 billion gallons by 2022. Higher carbon number alcohols, in addition to cellulosic ethanol and synthetic biofuels, could be used to meet this demand while adhering to the RFS2 corn-based ethanol limitation. Alcohols of carbon numbers 2 through 8 are chosen based on their chemical and engine-related properties.

Blend comparison metrics are developed from automotive industry trends, consumer expectations, U.S. fuel legislation, and engine requirements. The metrics are then used to create scenarios by which to compare higher alcohol fuel ...


Heat Transfer Analysis In A Paddle Reactor For Biomass Fast Pyrolyis, Ankith Ullal Jan 2017

Heat Transfer Analysis In A Paddle Reactor For Biomass Fast Pyrolyis, Ankith Ullal

Dissertations, Master's Theses and Master's Reports

Heat transfer analysis was performed on a novel auger reactor for biomass fast pyrolysis. As part of this analysis, correlations for specific heat capacity and heat transfer coefficients for biomass (sawdust) and sand (used as heat transfer medium) were developed. For sand, the heat transfer coefficient followed a power law distribution with reactor fill level and temperature. For raw biomass, the heat transfer coefficient also showed similar dependence on fill level, but was independent of temperature up to 300°C. These correlations were used in a one dimensional heat transfer model developed to calculate the heating time and heating rate ...


A Study Of High Temperature Heat Pipes And The Impact Of Magnetic Field On The Flow Of Liquid Metal, Udit Sharma Jan 2017

A Study Of High Temperature Heat Pipes And The Impact Of Magnetic Field On The Flow Of Liquid Metal, Udit Sharma

Dissertations, Master's Theses and Master's Reports

A study of high temperature heat pipe was conducted to understand its characteristics. A review of working fluid, temperature, wick structure, problems, operational limit and applications was done. Alkali metal were concluded as the most viable candidate for the working fluid.

The impact of three parameters namely magnetic field, heat flux and temperature was analyzed on the performance of HTHP (High Temperature Heat Pipe). The presence of magnetic field had the most considerable impact on reducing the pumping limit of the heat pipe while the temperature had almost negligible effect. Magnetic field results in the pressure drop and adversely affect ...