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Technical Paper

The Coaxial Cavity Resonator as a RF IC Engine Ignition Source

2001-03-05
2001-01-0987
The Quarter Wave Coaxial Cavity Resonator (QWCCR) plasma igniter is designed, from previous theoretical work, as an ignition source for an internal combustion engine. The present research has explored the implementation of the QWCCR into an internal combustion (IC) engine. The QWCCR design parameters of inner conductor length, loop geometry, and loop position were varied for two igniters of differing operating frequency. Variations of the QWCCR radio frequency (RF) parameters, as a function of engine geometry, were studied by placing the igniter in a combustion chamber and manually varying the crank position. Three identical igniters were fitted with dielectric inserts and the parameters were studied before and after ignition was sustained in a twin-cylinder engine. Optimal resonator geometries were determined. Radio frequency parameter invariance was found with respect to crank angle and piston distance. The first successful IC engine ignition using a QWCCR was achieved.
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

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

Continued Computational Investigation into Circulation Control for the V-22 Osprey Download Reduction

2005-10-03
2005-01-3187
The commercially available RNG k-e turbulence model with enhanced wall treatment found in Fluent 6.1 was used to solve the flow over a V-22 Osprey wing equipped with blowing slots. The solutions were then compared to experimental data. Good correlation between the computational and experimental data was found. Download on the wing from the rotors while the aircraft is operating in vertical take-off and landing mode was found to be reduced by the blowing slots.
Technical Paper

Development of a Remote Sensor Deployment System for Expanded C4ISR Use of the C-130 Aircraft

2005-10-03
2005-01-3395
Enhancing the capabilities of established airframes to meet expanded mission requirements is preferential to the design of specialized aircraft. The high cost associated with the research and development of a specialized aircraft platform has shifted the concentration towards the modification of existing aircraft to support multiple C4ISR missions. The recently developed Oculus sensor deployment system is one such example of this trend, providing a fully integrated aerial visual enhancement platform with multi-mission capabilities. This paper provides a short survey of the Oculus sensor pallet system and overviews some of the multiple guidelines used which ensure that various remote sensing technologies may be securely and simultaneously deployed.
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

Velocity Profile Measurements Under the Ramp of a Lockheed Martin C-130 Aicraft

2004-11-02
2004-01-3099
Predicting the aerodynamic forces in the wake of an object can be difficult using theoretical and computational methods. This is particularly true for airframes that have multiple engines and whose flight envelope involves the use of large control surfaces. One such aircraft is the C-130 which adds the further complication of a rear cargo door and ramp. Modeling the wake near the rear of this aircraft can be difficult and inaccurate unless validated against actual flight data. For this study a simple test apparatus, developed by the authors, was used to measure the velocity profile in the wake area of the rear cargo door of such an aircraft. The test apparatus contained 32 pressure ports, one of these ports was assigned to a static pressure probe. All pressures were referenced to an additional static pressure measured at the edge of the cargo ramp. The remaining, 31 pressure probes were distributed regularly between three vertical rake assemblies.
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

Experimental Investigation of Dielectrics for Use in Quarter Wave Coaxial Resonators

2007-04-16
2007-01-0256
Current research has involved manipulating the ignition inside of the combustion chamber. It has been demonstrated that an RF plasma flame can be generated from microwaves in a Quarter Wave Coaxial Cavity Resonator (QWCCR). By using this method, it may become possible for researchers to improve combustion and ignition characteristics of a modern internal combustion engine. Filling a plasma cavity with an appropriate dielectric medium can both alter electromagnetic properties and provide a suitable protective barrier to the harsh condition inside of a combustion cylinder. It is the purpose of this paper is to investigate both the operating frequency and quality factor of dielectric-filled cavities, as well as to suggest dielectrics that would be suitable for such an application.
Technical Paper

Potential Applications of the Stiller-Smith Mechanism in internal Combustion Engine Designs

1987-11-08
871225
With few exceptions most internal combustion engines use a slider-crank mechanism to convert reciprocating piston motion into a usable rotational output. One such exception is the Stiller-Smith Mechanism which utilizes a kinematic inversion of a Scotch yoke called an elliptic trammel. The device uses rigid connecting rods and a floating/eccentric gear train for motion conversion and force transmission. The mechanism exhibits advantages over the slider-crank for application in internal combustion engines in areas such as balancing, size, thermal efficiency, and low heat rejection. An overview of potential advantages of an engine utilizing the Stiller-Smith Mechanism is presented.
Technical Paper

Automobile Body Panel Color Measurement Test

1997-02-24
970995
It has been proposed that an automated remote color inspection of automobile body panels is possible with a reasonably precise color measurement. This paper outlines a test of a new 3D color measurement technology as applied to this task and presents the results of the first test. A camera is set up several feet away from a car body; a 3D orientation measuring system takes both 3D and color data from the car. The raw data is presented as a set of 3D graphs; the geometry-corrected data is also provided. Statistical analysis is presented to indicate system precision.
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

The Influence of Sinusoidal Piston Motion on the Thermal Efficiency of Engines

1987-10-01
871916
A new technique of translating linear to rotary motion, using the Stiller- Smith mechanism, can be applied to the design of internal combustion engines and compressors. This new mechanism produces purely sinusoidal motion of the pistons relative to crank angle, which is a different motion from that produced by a conventional slider-crank mechanism, Influence of this sinusoidal motion on thermodynamic performance of engines and compressors was investigated theoretically and experimentally. Data are presented from a numerical analysis of compression and of spark-ignited combustion. Also, pressure-time curves for a standard and a modified (long connecting rod) spark ignition engine are compared. All data confirm that there is little thermodynamic difference between the Stiller-Smith and slider-crank devices.
Technical Paper

Three-Dimensional Balancing of the Stiller-Smith Mechanism for Application to an Eight Cylinder I.C. Engine

1987-10-01
871917
The Stiller-Smith Mechanism employs a double cross-slider to convert linear reciprocating motion into rotational motion. It has previously been shown that a four-cylinder configuration utilizing this motion conversion device can be balanced in two dimensions. The inherent planar nature of this mechanism makes it possible to produce a compact, eight cylinder configuration for use as an internal combustion engine which is balanced in three dimensions. This paper develops and presents the necessary requirements for such a balanced engine. Relative merits of various configurations are discussed and analytical results of different balancing schemes are presented.
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.
Technical Paper

Downwash Wake Reduction Investigation for Application on the V-22 “Osprey”

2003-09-08
2003-01-3020
The downwash of the prop-rotor blades of the Bell/Boeing V-22 “Osprey” in hover mode creates an undesirable negative lift on the wing of the aircraft. This downforce can be reduced through a number of methods. Neglecting all other effects, such as power requirements, this research investigated the feasibility of using circulation control, through blowing slots on the leading and trailing edge of the airfoil to reduce the wake profile under the wing. A model was built at West Virginia University (WVU) and tested in a Closed Loop Wind Tunnel. The airfoil was placed normal to the airflow using the tunnel air to simulate the vertical component of the downwash experienced in hover mode. The standard hover mode flap angle of 67 degrees was used throughout the testing covered in this paper. All of these tests were conducted at a free stream velocity of 59 fps, and the baseline downforce on the model was measured to be 5.45 lbs.
Journal Article

Design of a Flywheel Based Energy Storage and Distribution System for Rural Villages in China

2009-04-20
2009-01-0525
There are 30 million people in remote, rural communities in China without access to electricity. The government of China has initiated an ongoing effort to provide constant, reliable power to these citizens. Renewable energy is being utilized to solve this problem, which necessitates the use of a storage medium for energy, because renewable energies (i.e. wind and/or solar power) are inherently intermittent, variable, and largely unpredictable. By storing excess energy when it is plentiful (for a maximum feasible time of two days) and distributing it to the community in times of scarcity, the intermittent power is effectively leveled and auxiliary power is provided. A high-inertia flywheel was designed for this application because of its simplicity, ease of maintenance, low cost, and reliability. This design addresses many problems including bearing losses, aerodynamic losses, and distribution losses. The proposed design consists of a six spoke layout with a large outer ring.
Technical Paper

The Rand-Cam Engine: A Pistonless Four Stroke Engine

1994-03-01
940518
The Rand-Cam engine is a positive displacement machine, operating on a four stroke cycle, which consists of a rotor with multiple axial vanes forming combustion chambers as the rotor and vanes rotate in a cam shaped housing. The cam housing, consisting of two “half-housings” or stators, contains a toroidal trough of varying depth machined into each stator. The two stators are phased so that the shallowest point on one trough corresponds to the deepest on the other. A set of six vanes, able to move axially through machined holes in the rotor, traverses the troughs creating six captured zones per side. These zones vary in volume with rotor rotation. Since each trough has two deep sections and two shallow sections with ramps in between, full four stroke operation is obtained between each pair of vanes in each trough, corresponding to twelve power “strokes” per revolution.
Technical Paper

Basic Design of the Rand Cam Engine

1993-03-01
930062
The Rand Cam engine is a novel design which avoids the use of pistons in favor of a cavity of varying size and shape. A set of vanes protrudes from a rotor into a circular trough in a stator. The vanes seal to the walls and base of the trough, which is of varying depth, and progress around the trough with rotation of the rotor. These vanes therefore pass through the rotor and are constrained to move parallel to the rotational axis. Intake and exhaust processes occur through ports in the stator wall which are revealed by the passing vanes. Advantages of the basic design include an absence of valves, reduction in reciprocating masses, presence of an integral flywheel in the rotor and strong fluid movement akin a swirl induced by the relative velocity between the rotor and stator.
Technical Paper

Engineering Modeling and Synthesis of a Rand Cam Engine Through CAD Parametric Techniques

1993-03-01
930061
In this paper an approach is presented for the system parameterization and synthesis of a Rand-Cam® Engine configuration based on an axial-cylindrical cam driven mechanism. This engine consists of a stationary axial-cylindrical cam on which axially moving pistons (vanes) sweep around the cam as they are driven by the rotor, providing the volume displacement as the rotor delivers the rotary output torque directly to the shaft. It has been documented that this engine configuration has some unique features that make it particularly suitable for high power to weight ratio applications. The modeling strategy makes use of higher order curve and surface modeling techniques and object modeling approaches based on profile extruding, blending operations and constructive solid geometry. Some of the resulting models are further used for finite element engineering analysis through a programmatic logic built into the parameterized general model.
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