Gerald J. Micklow

Florida Institute of Technology · Department of Mechanical and Aerospace Engineering

Numerous studies have indicated the danger while loading vehicles on large automobile transporters or car haulers. Data shows that the automobile transporting industry has the highest employee injury rate of any other industry, including underground coal mining which traditionally has a high rate. One area of high injury is the manual deployment of...

This paper is focused on the overview of after treatment systems, various combustion processes, recent advances related to exhaust pollutant emission reduction from after treatment systems, reduced fuel consumption and the role of gasoline direct injections on it, product formations, and ways to improve this technology.

A theoretical assessment of various fuels and additives which aid in increasing the performance parameters of rocket engines is performed. It is focused mainly on hybrid rocket engines and their behavior when operating on different fuels. By making a comparative study, the fuels to oxidizer combinations are analyzed in detail. One of the main studi...

A compressible Navier-Stokes flow solver and k-epsilon turbulence model have been developed to predict supersonic compression corner and shear layer flow fields. Compressibility and low Reynolds number effects are incorporated into the standard high Reynolds number form of the incompressible k-epsilon turbulence model to aid in the prediction of re...

In this research summary, numerical models and experimental approaches for analyzing the behavior of cryogenic, turbulent fluid flows in a rocket combustor are examined and compared. One new experimental method for determining probability density functions (PDFs) for droplet size and temperature reveals that these distributions can be multimodal wh...

Homogeneous Charge Compression Ignition (HCCI) engine has been invented to achieve the advantages of both diesel and gasoline engines. HCCI engine can run with a higher compression ratio like diesel engine in order to achieve high thermal efficiency. Meanwhile, like gasoline engine, the engine produces less NOx gas and particulate matters than dies...

Homogeneous Charge Compression Ignition (HCCI) engine has been invented to achieve the advantages of both diesel and gasoline engines. HCCI engine can run with a higher compression ratio like diesel engine in order to achieve high thermal efficiency. Meanwhile, like gasoline engine, the engine produces less NOx gas and particulate matters than dies...

With the rise of carbon emissions into the atmosphere on a worldly scale, there exists a need to improve the efficiency of the internal combustion engine. This research review seeks to answer that need through the use of chemical additives. Not only has published research shown that chemical additives can decrease carbon emissions and other particu...

Numerical simulations were performed in a port injected spark ignition (SI) race car engine with pentroof geometry. The study was performed for a premixed case with one-step global reaction mechanisms for gasoline, gasoline-methanol and gasoline-methanol-water blends of 1.8%, 3.6% and 5.4% at stoichiometric conditions. The purpose of the study was...

A simple methodology for gaseous injection simulations with KIVA-3V by repurposing the liquid injection subroutines is introduced and its capabilities and limitations are demonstrated through an in-depth mesh sensitivity study and compared to experimental literature results. It was shown that this methodology allows for the accurate simulation of r...

In the presented study, the effects of the ingestion of a stoichiometric hydrogen-oxygen mixture into the inlet air at engine speeds of 1300 and 3300 rpm on a Yanmar 6LY2A-STP marine Turbo-Diesel engine at rates that can practically be produced by on-board hydrogen generation systems were investigated through numerical simulations using the KIVA 3V...

This paper describes a novel method for extended expansion in a rotary combustion engine running ordinary gasoline. The engine consists of a toroidal-shaped piston that rotates around a drum to expand and evacuate the hot gas. There are several problems with today’s internal combustion (IC) engines. Current IC engines do not always have the necessa...

Numerical simulations were performed in a direct injection spark ignition engine (DISI) with pentroof geometry. The study was performed for a premixed case with one-step gasoline global reaction mechanism and gasoline-hydrogen blends of 1%, 2% and 3% at equivalence ratios of 0.5 to 1. The purpose of the study was to analyze the combustion and therm...

The scarcity of experimental data for soy biodiesel fuel properties covering the full temperature range from injection to critical temperature reduces the reliability and accuracy of fuel property estimation techniques, and hence engine simulations. This study reviews and validates soy biodiesel fuel property estimation techniques indirectly using...

Through an extensive literature survey the important characteristics of Low Temperature Combustion (LTC) Engine operation were investigated. Previous research indicates that low temperature combustion is capable of producing ultra-low nitrogen oxides (NOx) and soot emissions. The principle of LTC is based on enhancing the air fuel mixing and reduci...

The desired product composition and thermodynamic properties produced by a closed combustion chamber is heavily influenced by reactant distribution and ignition source. A fundamental and defining mechanism behind these reaction properties is the burn rate which is a strong function of local equivalence ratio gradient and vaporous fuel concentration...

Understanding the physics and chemistry involved in diesel combustion, with its transient effects and the inhomogeneity of spray combustion is quite challenging. Great insight into the physics of the problem can be obtained when an in-cylinder computational analysis is used in conjunction with either an experimental program or through published exp...

The design of a complex system such as an automobile consists of the design of many highly complex subsystems. To address this level of complexity, traditionally the designers use a sequential and spiral design process with the goal of achieving a final feasible design that meets all of the competing and, sometimes, conflicting subsystem requiremen...

The combination of superior fuel economy and durability has made compression ignition direct injection diesel engines popular worldwide. However, these engines can emit large amounts of ozone-forming pollutants and particulates and so are being subjected to increasingly stringent regulations that require continual improvements in the combustion pro...

In recent years, a significant amount of high-speed combustion research has been directed toward optimization of scramjet combustors, and in particular on the efficiency of fuel-air mixing and reaction taking place in the engine. This article numerically investigates the flow characteristics of a dual-mode scramjet-combustor configuration. Results...

The in-cylinder flow field was numerically investigated for a four-valve per cylinder Caterpillar diesel CAT3401 engine. The computer program used was the KIVA3V code developed by Los Alamos National Laboratory. To assess the effect of modelling assumptions made during the domain discretization, three grid models were developed. The first grid or t...

A zero dimensional computer code was developed to predict the performance of an spark ignition internal combustion fuel inducted engine. The code can be used to predict engine performance for automotive and racing applications. Expressions for turbulent flame speed were developed based on turbulent flame intensity and cylinder geometry. This turbul...

This study presents a computationally efficient numerical model that accurately predicts complex spray distribution and spray penetration for a direct injection compression ignition engine configuration. Experimental data obtained from available literature is used to construct a semi-empirical numerical model. A modified version of a multidimension...

A three-dimensional numerical study is conducted to investigate the flow characteristics of a dual-mode scramjet-combustor configuration. The present study is a part of an on-going research to simulate the mixing and combustion in scramjet engines. The paper presents results of a combustor model with a single unswept wall-mounted raised (compressio...

The present study reports numerical analysis of turbulent jets. Effects of various parameters on the characteristics of two-dimensional turbulent plane parallel and offset jets are investigated. The emphasis is put on the effect of the wall angle and nozzle width on the location merging and the combining points. The flowfield under consideration ar...

This paper reports a numerical study to investigate the effect of various parameters on the mixing characteristics of two-dimensional turbulent co-flowing jets. The paper is a part of an ongoing research to simulate and investigate the mixing and combustion processes of subsonic jets. Results are obtained with a finite volume CFD code. Turbulence i...

Understanding the physics and chemistry involved in spray combustion, with its transient effects and the inhomogeneity of the spray is quite challenging. For efficient operation of both internal combustion and gas turbine engines, great insight into the physics of the problem can be obtained when a computational analysis is used in conjunction with...

A three-dimensional unsteady turbulent compressible Navier-Stokes solver, KIVA3V, was utilized in the present study to investigate the intake and in-cylinder flowfield of a four-valve direct injection compression ignition engine. Successful modelling of internal combustion engine configurations is highly dependent upon the generation of a quality g...

With energy conservation and pollutant emission of paramount importance in today's society, it has emphasized the need for aerodynamic drag reduction in the automotive sector. Innovative ideas, better visualization, reduced time in the design process, and cost effective "computational testing" is all put together is the use of Computational Fluid D...

The current study reports numerical analysis of turbulent jets. Effects of various parameters on the characteristics of two-dimensional turbulent plane parallel and offset jets are investigated. The emphasis is put on the effect of the wall angle and nozzle width on the location merging and the combining points. The flowfield under consideration ar...

Previous research has shown that the homogeneous charge compression ignition (HCCI) combustion concept holds promise for reducing pollutants (i.e. NOx, soot) while maintaining high thermal efficiency. However, it can be difficult to control the operation of the HCCI engines even under steady state running conditions. Power density may also be limit...

A multistage combustion model for diesel engines is presented in this paper. Three combustion stages, ignition of diesel, premixed combustion and diffusion combustion, are considered in the combustion process in a typical medium speed direct injection diesel engine. The transition from the ignition delay to the premixed combustion stage occurs when...

Research has shown that a large amount of natural gas (NG) is unburned at light loads in an NG fuelled/micro-pilot diesel compression ignition engine. A mechanism of unburned hydrocarbon (HC) reduction using multiple injections of micro-pilot diesel has been proposed in this paper. Multidimensional computations were carried out for a dual-fuel engi...

Successful modelling of combustion systems depends on an adequate as well as a computationally efficient description of the reaction mechanisms. For a typical medium speed compression ignition direct injection (CIDI) engine under normal operating conditions, from 70 to 95 per cent of the injected fuel is in the vapour phase at the start of combusti...

A quasi-one-dimensional computer code based on a fuel-air cycle analysis was developed to predict the performance of two- and four-stroke fuel-inducted engines. The analysis was developed to provide boundary conditions for a finite element analysis to predict thermal and mechanical loading of carbon-carbon pistons for use in advanced internal combu...

The development of a low cost space transportation system requires that the propulsion system be reusable, have long life, with good performance and use low cost propellants. Improved performance can be achieved by operating the engine at higher pressure and temperature levels than previous designs. Increasing the chamber pressure and temperature,...

The use of a staged turbine combustor (STC) for reducing the pollutant emissions is currently under study because it offers a broad operational range due to the good flame stability of the RB zone. A numerical study was performed to investigate chemically reactive flow with sprays inside a STC combustor using a modified version of the KIVA-2 code....

The performance of high shear axial inflow/radial outflow airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. Curved vanes usually exhibit lower losses but straight vanes are also used due to lower cost and ease of manufacture. These type of vanes often operate under highly stalled condi...

This study presents the results of numerical simulations of single stage transonic axial-flow compressors. The numerical scheme used solves the unsteady quasi-three-dimensional thin-layer Navier-Stokes equations. In the first part of the study, the validation of the numerical scheme for advanced transonic axial-flow compressor stages is presented....

The performance of high shear airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. The vanes may be of the straight or curved type. Curved vanes usually exhibit lower losses but straight vanes are also used due to lower cost and ease of manufacture. These type of vanes often operate under...

In gas turbine combustors, enhanced atomization through the whole combustor region is essential for satisfactory performance since droplet size and distribution can have direct impact on almost all key aspects of combustion. To predict these flows, KIVA-II, a three-dimensional full Reynolds-averaged Navier-Stokes solver with the capability to handl...

A numerical study was performed to investigate the chemically reactive flow with liquid spray injection in a staged combustor concept for reducing pollutant emissions. The staged combustor consists of an airblast atomizer, a rich bum section, a converging connecting pipe, a quick mix zone, a diverging connecting pipe, and a lean combustion zone. Fo...

Computations of flow show performance of high-shear airblast fuel injector in gas-turbine engine enhanced by use of appropriately proportioned twisted (instead of flat) dome swirl vanes. Resultant more nearly uniform fuel/air mixture burns more efficiently, emitting smaller amounts of nitrogen oxides. Twisted-vane high-shear airblast injectors also...

Requirements to reduce the emissions of pollutants from gas turbines used in aircraft propulsion and ground based power generation have led to consideration of lean premixed/prevaporized (LPP) combustion concept. This paper describes some of the LPP flame tube analyses performed at the NASA Research Center with KIVA-2, a well-known multi-dimensiona...

The KIVA-II code was modified to calculate the 3D flow field in a typical annular gas turbine combustor. The airblast fuel nozzle, cooling baffle, cooling slots, primary and dilution jets, and effusion cooling (bleed) pads were accounted for in this calculation. The turbulence and combustion were modeled using the k-epsilon model and laminar Arrhen...

The performance of high shear airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. The vanes may be of the straight or curved type. Curved vanes usually exhibit lower losses but straight vanes are also used due to lower cost and ease of manufacture. These type of vanes often operate under...

A modified version of the KIVA-II code was used to obtain a multidimensional numerical solution for the turbulent two-phase chemically reacting flows inside a staged turbine combustor (STC). The STC under consideration is equipped with an advanced airblast fuel nozzle and encompasses a fuel nozzle (FN), a rich-burn (RB) zone, a converging connectin...

A rich burn/quick mix/lean burn (RQL) combustor concept for reducing pollutant emissions is currently under investigation at the NASA Lewis Research Center (LeRC). A numerical study was performed to investigate the chemically reactive flow with liquid spray injection for the RQL combustor. The RQL combustor consists of an airblast atomizer fuel inj...

The KIVA-2 code was modified to allow calculation of the flow field in a Richburn/Quick quench/Lean burn (RQL) staged gas turbine combustor including the airblast fuel nozzle. The results illustrate the complicated flow field present in RQL combustors. In particular the thermal protection requirements of the quick-quench mixer used in this study ma...

A parametric study is conducted to investigate the effect of nozzle lip geometry on nozzle fuel distribution, emissions and temperature distribution for a rich burn section of a rich burn/quick quench/lean burn combustor. It is seen that the nozzle lip geometry greatly affects the fuel distribution, emissions and temperature distribution. It is det...

A general two dimensional flow solver is presented for internal or external compressible flow fields with or without embedded shocks. Options allow for the solution of the steady or unsteady Euler, thin layer or full Reynolds averaged Navier Stokes equations. A cell centered conservative finite volume technique is utilized with a constant artificia...

For advanced gas turbine engines, two combustor systems, the lean premixed/prevaporized (LPP) and the rich burn/quick quench/lean burn (RQL) offer great potential for reducing NO(x) emissions. An important consideration for either concept is the development of an advanced fuel injection system that will provide a stable, efficient, and very uniform...

A mathematical anaysis predict the unsteady aerodynamic utilizing semi actuator theory environment for a cascade of airfoils harmonically oscillating in choked flow was developed. A normal shock is located in the blade passage, its position depending on the time dependent geometry, and pressure perturbations of the system. In addition to shock dyna...

To investigate the effects of a friction reducing oil additive, a comprehensive test plan was developed which included road, track and dynamometer testing. It was seen that by treating the vehicles engine and drive train with a friction reducing additive, a significant reduction in fuel consumption was obtained. INTRODUCTION For modern vehicles, it...

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1989. Vita. Abstract. No film copy made for this title. Includes bibliographical references (leaves 97-101).