Engineering Commons^™

Disk Engine With Circumferential Swirl Radial Combustor, Brian Bohan, Marc Polanka, Bennett Staton

AFIT Patents

A disk engine and system configured to provide high power at a reduced axial length is disclosed herein. The disk engine includes a radial compressor, a compressor discharge manifold positioned circumferentially about compressor, a combustion chamber positioned within the discharge manifold and a radial turbine positioned radially inward of the combustion chamber.

Thermal Ignition Of A Combustible Over An Inclined Hot Plate, Salaika Parvin, Nepal Chandra Roy, Rama S. R. Gorla

Faculty Publications

In this study, the ignition characteristics and the flow properties of the mixed convection flow are presented. Detailed formulations of the forced, natural and mixed convection problems have been discussed. In order to avoid inconvenient switch between the forced and natural convection we introduce a continuous transformation in the mixed convection. We make a comparison between these situations which reveal a good agreement. For mixed convection flow, the ignition distance is explicitly expressed as a function of the Prandtl number, reaction parameter and wall temperature. It has been observed that owing to the increase of the aforesaid parameters, the thermal …

Development Of Reduced Chemical Kinetic Models For The Numerical Simulation Of Combustion And Emissions Behavior Of Representative Conventional And Bio-Derived Fuels, Mazen A. Eldeeb

Mineta Transportation Institute Publications

The study addresses two of the main challenges facing combustion modeling for transportation fuels: simultaneous simulation of non-related combustion problems and reducing the computational cost of the modeling process itself. To address the first challenge, researchers determine a characteristic flame time from thermal diffusivity and laminar burning velocity. Researchers examine parametric dependence of flame time and ignition delay time on pressure, temperature and equivalence ratio for methane, based on validated chemical kinetic mechanisms. The study reveals flame time and ignition delay time show similar temperature dependence, flame time has stronger dependence on equivalence ratio and weaker dependence on pressure than …

Computational Analysis Of A New Planar Mixing Layer Flame Configuration To Study Soot Inception, Carmen Ciardiello

Honors Scholar Theses

The production of soot is omnipresent in society today. Soot is the product of many of the combustion processes that provide the bulk of the usable energy throughout the world. Furthermore, soot particulate poses a great danger to both the environment and all forms of life on Earth. It has proven to pollute ecosystems, foster health problems for human beings, and degrade air quality [1].

These dangers make studying and understanding soot particulate paramount for improving the quality of life. Thus, this study introduces a new flame configuration for studying soot inception. Presently, various common flame configurations have been found …

A Quasi-Monte Carlo Solver For Thermal Radiation In Participating Media, Joseph Farmer, Somesh Roy

Mechanical Engineering Faculty Research and Publications

The Monte Carlo (MC) method is the most accurate method for resolving radiative heat transfer in participating media. However, it is also computationally prohibitive in large-scale simulations. To alleviate this, this study proposes a quasi-Monte Carlo (QMC) method for thermal radiation in participating media with a focus on combustion-related problems. The QMC method employs low-discrepancy sequences (LDS) in place of the traditional random numbers. Three different low-discrepancy sequences – Sobol, Halton, and Niederreiter – were examined as part of this work. The developed QMC method was first validated against analytical solutions of radiative heat transfer in several one-dimensional configurations. Then …

An Efficient Monte Carlo-Based Solver For Thermal Radiation In Participating Media, Joseph Farmer, Somesh Roy

Mechanical Engineering Faculty Research and Publications

Monte Carlo-based solvers, while well-suited for accurate calculation of complex thermal radiation transport problems in participating media, are often deemed computationally unattractive for use in the solution of real-world problems. The main disadvantage of Monte Carlo (MC) solvers is their slow convergence rate and relatively high computational cost. This work presents a novel approach based on a low-discrepancy sequence (LDS) and is proposed for reducing the error bound of a Monte Carlo-based radiation solver. Sobols sequence – an LDS generated with a bit-by-bit exclusive-or operator – is used to develop a quasi-Monte Carlo (QMC) solver for thermal radiation in this …

Pore-Resolving Simulation Of Char Particle Gasification Using Micro-Ct, Greg Hingwah Fong, Scott Jorgensen, Simcha L. Singer

Mechanical Engineering Faculty Research and Publications

Understanding the interaction between transport, reaction and morphology at the scale of individual char particles is important for optimizing solid fuel gasification and combustion processes. However, most particle-scale models treat porous char particles as an effective porous continuum, even though the presence of large, irregular macropores, voids and fractures render such upscaled treatments mathematically invalid, and the models non-predictive. A new modeling framework is therefore proposed to elucidate the impact of morphology on char particle gasification and combustion. A pore-resolving, transient, three-dimensional simulation for gasification of a realistic coal char particle is developed based on X-ray micro-computed tomography (micro-CT). The …

The Feasibility Of Utilising Compressed Natural Gas As Part Of A Systematic Approach To Establishing The Necessary Groundwork For The Hydrogen Based Transport Economy, James Brunton, John Howlett, David Kennedy

Conference Papers

One key objective for vehicle manufacturers is to develop technology and infrastructure to facilitate the progression from combustion to conversion by the year 2050. In the short to medium term however, the combustion of fossil fuels such as petrol and diesel, coupled with advanced transmission innovations and emission control technology that are governed by strict Euro VI regulations appears to be the main path forward for the transport sector and the environment. This paper presents the feasibility of utilising the developing compressed natural gas network capabilities as part of a systematic approach to establishing the necessary groundwork for a hydrogen …

Performance Evaluation Of Palm Oil-Based Biodiesel Combustion In An Oil Burner, Abdolsaeid Ganjehkaviri, Mohammad Nazri Mohd Jaafar, Seyed Ehsan Hosseini, Anas Basri Musthafa

Faculty Publications - Mechanical Engineering

This paper presents an experimental investigation of the combustion characteristics of palm methyl ester (PME), also known as palm oil-based biodiesel, in an oil burner system. The performance of conventional diesel fuel (CDF) and various percentages of diesel blended with palm oil-based biodiesel is also studied to evaluate their performance. The performance of the various fuels is evaluated based on the temperature profile of the combustor's wall and emissions, such as nitrogen oxides (NOx) and carbon monoxide (CO). The combustion experiments were conducted using three different oil burner nozzles (1.25, 1.50 and 1.75 USgal/h) under lean (equivalence ratio (φ) = …

La0.7Sr0.3Fe0.7Ga0.3O3-Δ As Electrode Material For A Symmetrical Solid Oxide Fuel Cell, Zhibin Yang, Yu Chen, Chao Jin, Guoliang Xiao, Minfang Han, Fanglin Chen

Faculty Publications

In this research, La_0.7Sr_0.3Fe_0.7Ga_0.3O_3−δ (LSFG) perovskite oxide was successfully prepared using a microwave-assisted combustion method, and employed as both anode and cathode in symmetrical solid oxide fuel cells. A maximum power density of 489 mW cm⁻² was achieved at 800 °C with wet H₂ as the fuel and ambient air as the oxidant in a single cell with the configuration LSFG|La_0.8Sr_0.2Ga_0.83Mg_0.17O_3−δ|LSFG. Furthermore, the cells demonstrated good stability in H₂ and acceptable sulfur tolerance.

Development Of Oxidizer Flow Control For Use In Hybrid Rocket Motors Of The Scientific Sounding Rocket Scale, Luke Saindon

Honors College

To successfully build a rocket engine with variable thrust you must devise a reliable and robust oxidizer flow control system. The goal of this thesis is to contribute to the goal of building a variable thrust (throttled) hybrid rocket engine, which could eventually be used to power scientific sounding rockets. A variable thrust hybrid engine would increase reusability, flexibility, and capability of almost any small rocket.

Specifically, this thesis work regards the development of the closed loop oxidizer flow control system. To do this, a small test rig was built in the lab that consists of all the components in …

Factors Affecting The Performance Of Kerosene Cook Stoves, Edna B. Snyder

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The purpose of this investigation was to learn the effect of constructional details of the burner and the framework on the performance of kerosene stoves. Six stoves were used, four of the long-chimney type and two of the short-chimney type. Of the long-chimney burners, three were from the same manufacturer; the fourth was similar in appearance, but differed in performance. Of the short chimneys one burner used a wick, the other a lighting ring. The effect of: (1) draft variations and constructional details and (2) the framework on the heating time and thermal efficiency of stoves was studied.