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Technical Paper

High-Level Modeling of an RF Pulsed Quarter Wave Coaxial Resonator with Potential use as an SI Engine Ignition Source

2008-04-14
2008-01-0089
Significant environmental and economic benefit could be obtained if spark ignited (SI) engines could be made more efficient. Engine operation using leaner fuel air mixtures at higher power densities and pressures promise higher thermal efficiencies. Mixtures required for such operation are often difficult to ignite with traditional spark plugs. In pursuit of better ignition sources, this paper presents a high-level model of an alternative microwave plasma ignition source under development. In this publication, atmospheric measurements of a pulsed microwave ignitor are used to derive an empirical model that will allow for control and increased energy delivery to the device. The model accounts for a simplistic plasma formation delay, a drop in resonance frequency as a result of plasma formation, and a subsequent change in associated microwave reflection coefficient.
Technical Paper

Automatic Control Implementation and Upgraded Electrical System Design for the Oculus 2.0 Sensor Platform

2007-09-17
2007-01-3874
The Oculus sensor deployment platform research and development was conducted by the Center for Industrial Research Applications (CIRA) at West Virginia University (WVU). Oculus is a cost-effective reconnaissance platform available for use on a C-130 aircraft variants B through H. This system has a base of two standard MIL-463L pallets, an operators station and sensor pallet, that are loaded and rolled into place. The fore pallet or operator’s station holds three controllers, processing equipment for sensor data, and power regulation equipment. The aft pallet, or sensor pallet, located on the cargo ramp, contains sensors that, when in position, can be pointed at the ground. These reconnaissance sensors are situated in a pod that is mounted to four arms to allow more than 200 degrees of rotation, and are mounted to a movable plate that allow for linear movement.
Technical Paper

Sealing and Structural Enhancement System for the Rear Cargo Ramp of a C-130 Aircraft

2007-09-17
2007-01-3883
At flight levels above the ceiling of 10,000 feet, during the operational phase of a sensor deployment system for a C-130 aircraft, it becomes necessary to seal the cargo hold to maintain pressure for the safety and comfort of the crew and operators. In order for the sensor deployment System to have full mission support capabilities for DoD reconnaissance needs, a system must be designed where-by the cargo area may be sealed once the system has been deployed. Currently, with the sensor pod in position, the ramp can be closed to within a few inches of the locked position. The door in this position, for stability during flight, must be locked and structurally supported to maintain the aircrafts design requirements. This presents the first of a series of issues that must be examined for the success of the final design. To seal the remaining area, an expanding “bladder-seal” has been developed.
Technical Paper

Evaluation of a Portable Micro-Dilution Tunnel Particulate Measurement System

2005-10-24
2005-01-3789
The Federal Test Procedure (FTP) for heavy-duty engines requires the use of a full-flow tunnel based constant volume sampler (CVS) which is costly to build and maintain, and requires a large workspace. A portable micro-dilution system that could be used for measuring on-board, in use emissions from heavy duty vehicles would be an inexpensive alternative compared to a full-flow CVS tunnel, as well as requiring significantly less workspace. This paper evaluates such a portable particulate matter measuring system. This micro-dilution tunnel operates on the same principle as a full-flow tunnel, however dilution ratios can be more easily controlled with the micro dilution system. The dilution ratios for the micro-dilution system were maintained at least four to one, as per ISO 8178 requirements, by measuring the mass flow rates of the dilution air and dilute exhaust.
Technical Paper

Design of a Portable Micro-Dilution Tunnel Particulate Matter Emissions Measurement System

2005-10-24
2005-01-3795
The Federal Test Procedure (FTP) for heavy-duty engines requires the use of a full-flow tunnel based constant volume sampler (CVS). These are costly to build and maintain, and require a large workspace. A small portable micro-dilution system that could be used on-board, for measuring emissions of in-use, heavy-duty vehicles would be an inexpensive alternative. This paper presents the rationale behind the design of such a portable particulate matter measuring system. The presented micro-dilution tunnel operates on the same principle as a full-flow tunnel, however given the reduced size dilution ratios can be more easily controlled with the micro dilution system. The design targets dilution ratios of at least four to one, in accordance with the ISO 8178 requirements. The unique features of the micro-dilution system are the use of only a single pump and a porous sintered stainless steel tube for mixing dilution air and raw exhaust sample.
Technical Paper

Continued Computational Investigation into Circulation Control for the V-22 Osprey Download Reduction; Blowing Slot Optimization

2006-08-30
2006-01-2396
Previous studies have shown that using blowing slots can reduce the effects of the rotor downwash on the main wing of a tilt-rotor aircraft, particularly the V-22 Osprey. The current study investigates the placement and air velocity of the leading edge blowing slot for optimization of the download reduction. The realizable turbulent kinetic energy - rate of dissipation (rke) numerical model available in Fluent 6.2.12 was used to model the flow involved under the rotors and the subsequent downwash around the main wing. It was found that the leading edge blowing slot is most beneficial when it is placed just upwind of the separation point without blowing slots. In the current investigation the optimal configuration is found between 0 percent and 1 percent of the chord length.
Technical Paper

Maintenance Issues and Fail Safes of the Oculus Sensor Platform System

2005-10-03
2005-01-3427
When designing the Oculus sensor platform, many safety issues such as designing fail safes, adapting to flying situations, and examining situations produced by exposure to real-world conditions were taken into consideration. When predicting maintenance issues, environmental conditions that the platform will have to encounter were assessed. A material that was lightweight and strong enough to withstand the harsh environmental conditions experienced outside the C-130 aircraft was needed. In addition to the material used, another issue addressed was the ability to repair the platform easily and efficiently. Normal operations expose the components to significant wear and tear, which requires the replacement of parts to maintain safe operations. Oculus was constructed to allow for component replacement without deconstruction of the entire platform. While environmental factors were a concern, mechanical design and functionality, along with safety, was vital to the project.
Technical Paper

Experimental Stress/Strain Analysis of a Standardized Sensor Platform for a C-130 Aircraft

2005-10-03
2005-01-3426
Project Oculus is an in-flight deployable mechanical arm/pod system that will accommodate 500 pounds of sensor payload, developed for a C-130 military aircraft. The system is designed for use in counter narco-terrorism and surveillance applications by the Department of Defense and the National Guard [1]. A prototype of the system has been built and is in the testing/analysis phase. The purpose of this study was to analyze the actual stresses and strains in the critical areas found using previous Finite Element (FE) simulations and to ensure that acceptable safety requirements have been met. The system components tested will be redesigned, tested, and reconstructed in the case of unacceptable safety factors or if more reliable methods can be implemented. The system was built to be deployed and retracted in flight, to avoid causing any problems in take off and landing.
Technical Paper

Hub Connection Simulation of a Sensor Platform System

2005-10-03
2005-01-3425
In this analysis the structural integrity of the rotational system of a standardized roll-on, roll-off sensor pallet system was authenticated. The driving force behind this analysis was to ensure the structural integrity of the system and to locate the areas with optimization potential. This process will ideally lead to the weight reduction of individual components thereby allowing for the transportation of greater cargo during flight. Scaling down of these excessive areas will also allow for a reduced production cost and an increase in efficiency of the system. The study was comprised of the failure susceptibility of the individual components of the system. The major results include the optimization potential of individual components, as well as strategically rating and categorizing the failure capability of the components.
Technical Paper

Electromagnetic Compliance Issues of Project Oculus

2005-10-03
2005-01-3394
Project Oculus, an experimental configurable sensor platform for deploying airborne sensors on a C-130 aircraft, is currently in its pre-flight testing phase. The electronics driving the platform are available commercially off the shelf (COTS) and as such are not automatically rated to comply with stringent military electromagnetic standards as defined in MIL-STD-461. These COTS electronics include efficient switching power converters, variable frequency motor drives (VFD), and microprocessor based equipment, all of which can present electromagnetic interference (EMI) issues. Even in a design where EMI issues were not considered up front, it is often possible to bring the overall configuration into compliance. Switching and digital clock signals produce both conducted and radiated noise emissions. Long cable runs and enclosure apertures become noise transmitting antennas. Large switching currents place noise on the power lines causing interference with other equipment.
Technical Paper

Design of a Standardized Roll-On, Roll-Off Sensor Pallet System for a C-130 Aircraft

2004-11-02
2004-01-3092
The development of a standardized roll-on, roll-off (RoRo) sensor pallet system for a C-130 aircraft was conceived by the National Guard and the Counter Narco-Terrorism Technology Development Office to assist in counterdrug reconnaissance activities within the United States and surveillance and reconnaissance missions worldwide. West Virginia University was contracted to perform the design and development of this system because of their innovative design ideas. Before development, the design parameters were established by these two DoD agencies, their mission requirements and by the limitations of the C-130 aircraft. These limitations include using Commercial off the Shelf (COTS) and Government off the Shelf (GOTS) items when developing the system that must be universal on all C-130 aircrafts variants B thru H. Further design criteria are by the limitations of the C-130 aircraft and its existing mission requirements.
Technical Paper

Sensitivity Analysis of the C-130 Sensor Deployment System Arm Using Finite Element Methods

2004-11-02
2004-01-3098
The purpose of this study was to optimize the current design of the roll-on, roll-off sensor deployment system support arm for the C-130 Hercules. The Department of Defense (DOD) and the National Guard (NG) will be using these sensor pallet systems in a variety of command and control configurations for counter narco-terrorism applications along with several other applications. The original design for the sensor deployment arm will be drawn using CAD, and then a Finite Element Analysis will be modeled and analyzed using Pro/ENGINEER and Pro/MECHANICA. This will show the stress concentrations and the areas where weight can be saved. The most concerning variable will be the height of the mechanical arm attachment. By decreasing that height, and shortening the mechanical arm, the moments will decrease, and the required torque will be less.
Technical Paper

Thermal Modeling of an Axial Vane Rotary Engine

1998-02-01
980123
A complete three-dimensional thermal finite element analysis has been performed for the Beta version of an axial vane rotary engine. This work investigated the effects of the heat flow for two different geometric designs (kinematic inversions): rotor turning with vane turning and cams turning with a non-rotating vane. The output from a modified zero dimensional combustion code was used to establish the thermal boundary conditions in the finite element model. An iterative procedure between the thermal finite element model and the zero dimensional code was used to obtain the component wall temperature profile. Updating the combustion model wall temperature resulted in different thermal characteristics than those from the constant wall temperature solution. The thermal analysis provided a quantitative comparison of the different geometric versions of the engine, showing where improvements must be made.
Technical Paper

Modeling the Radio Frequency Coaxial Cavity Plasma Ignitor as an Internal Combustion Engine Ignition System

1998-02-23
980168
A quarter-wave radio frequency coaxial cavity plasma ignitor can be used to generate a combustion-initiating energy source in an internal combustion engine. This paper outlines research results on the development of such an ignitor. The system, which operates in the 820 - 900 MHz frequency range, uses a high Q quarter-wave cavity that generates plasma when resonating. Pressure testing has shown that the device can generate plasmas at spark ignition compression pressures. A resonator operating at these frequencies has been attached to a static combustion chamber and modeled numerically in order to determine the operational characteristics of the device in a combustion chamber.
Technical Paper

Simulation of a Continuously Variable Power Split Transmission

1999-03-01
1999-01-0062
Continuously variable transmissions promise to improve the performance and drivability of vehicles. The design and implementation of continuously variable transmissions for medium or large displacement (power) engines have been hampered by the power limitations of the belts. A continuously variable transmission with a power split design (CVPST) has been developed to minimize the loading on the belt while providing for increased power transfer compared to existing designs. To aid in the design and development of this CVPST, a simulator program has been developed. The simulator can be used to optimize the CVPST and to compare with other transmissions. Finally, an optimized CVPST design is presented.
Technical Paper

Thermodynamic implications of the Stiller-Smith Mechanism

1987-02-01
870615
The Stiller-Smith mechanism is a new mechanism for the translation of linear motion into rotary motion, and has been considered as an alternative to the conventional slider-crank mechanism in the design of internal combustion engines and piston compressors. Piston motion differs between the two mechanisms, being perfectly sinusoidal for the Stiller-Smith case. Plots of dimensionless volume and volume rate-change are presented for one engine cycle. It is argued that the different motion is important when considering rate-based processes such as heat transfer to a cylinder wall and chemical kinetics during combustion. This paper also addresses the fact that a Stiller-Smith engine will be easier to configure for adiabatic operation, with many attendant benefits.
Technical Paper

The Stiller-Smith Engine: Floating Gear Analysis

1987-02-01
870613
The Stiller-Smith Engine employs a non-standard gear train and as such requires a closer examination of the design and sizing of the gears. To accomplish this the motion of the Stiller-Smith gear train -will be compared to more familiar arrangements. The results of a kinematic and dynamic analysis will introduce the irregular forces that the gears are subjected to. The “floating” or “trammel” gear will be examined more closely, first stochastically and then with finite element analysis. This will pinpoint high stress concentrations on the gear and where they occur during the engine cycle, The configuration considered will be one with: an output shaft, negligible idler gear forces, and floating gear pins that are part of the connecting rods rather than the floating gear. Various loading techniques will be discussed with possible ramifications of each.
Technical Paper

The Stiller-Smith Engine-The Dewelopment of a New Environment for High-Tech Materials

1987-01-20
870721
New high-tech materials which are anticipated to revolutionize the internal combustion engine are being created everyday. However, their actual utilization in existing engines has encountered numerous stumbling blocks. High piston sidewall forces and thermal stresses are some of the problems of primary concern. The Stiller-Smith Engine should provide an environment more conducive to the use of some of these materials. Absent from the Stiller-Smith Engine is a crankshaft, and thus a very different motion is observed. Since all parts in the Stiller-Smith Engine move in either linear or rotary fashion it is simple to balance. Additionally the use of linear connecting rod bearings changes the location of the sidewall forces thus providing an isolated combustion chamber more tolerant to brittle materials and potential adiabatic designs. Presented herein is the development of this new engine environment, from conceptualization to an outline of present and future research.
Technical Paper

A Compression Ignition Engine Comparison Between a Slider-Crank and a Cross-Slider Based Engine

1990-02-01
900131
The Scotch yoke in its various forms and inversions has received considerable attention as possible alternatives to the slider-crank for internal combustion engine use. As a recent entry, the Stiller-Smith Mechanism has shown promise as being a viable and strong option. In this study emphasis was placed on comparing the number and similarity of mechanism components and the balancing aspects of these components, implications of component and linkage motions, the severity of loading experienced by similar bearing surfaces within the engines, and some of the friction losses associated with these new motions. It was found that the Stiller-Smith Engine has significantly fewer moving parts. It was also found that journal bearings in the slider-crank engine were more severely loaded than those in the Stiller-Smith Engine. The linear reciprocating bearings in the Stiller-Smith Engine were more heavily loaded than the slider-crank piston skirts.
Technical Paper

Supression of Bearing Vibrations by Using Fiber-Reinforced Composites

1989-02-01
890547
The potential benefits of using advanced fiber-reinforced composites as an alternative to metallic alloys has been investigated for the design and fabrication of connecting rods in motion conversion mechanisms for internal combustion engines. Two types of mechanisms have been selected for this analysis: the common slider-crank mechanism and the new. Stiller-Smith Mechanism, in which the crankshaft is replaced by a floating gear system. An improved finite-element elastodynamic model, which includes the effects of longitudinal, bending and shear deformations, has been developed in order to quantify the relationships between the levels of bearing loads and vibrations of such mechanisms and the material design of their connecting-rods. An extensive parametric study has been conducted on the material system, the lay-up and the cross-sectional dimensions of elastic connecting rods, made of helically wound composite materials.
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