Papers by Jonathan Rhéaume
SAE technical paper series, Sep 20, 2016
The goal of this project was to facilitate the transfer of an eight-year-old student with cerebra... more The goal of this project was to facilitate the transfer of an eight-year-old student with cerebral palsy from her wheelchair to an existing standing assist device by designing an attachment for the standing device. The transfer to and from the standing device used to require two aides, which was demanding in the school environment. A four-bar slider mechanism, driven by a linear actuator, was designed to rotate a frame from a position over her wheelchair to the standing device. The client is suspended from the crossbar of this frame in a quick to don and stable harness. Additionally, the transfer mechanism has a small footprint outside of the initial device, which was important for use in a public school. The mechanism facilitates the client's transfer by a single aide more quickly and with less physical exertion.
Solid state electrochemical sensors that measure nitrogen oxides (NO x) in lean exhaust have been... more Solid state electrochemical sensors that measure nitrogen oxides (NO x) in lean exhaust have been investigated in order to help meet future on-board diagnostic (OBD) regulations for diesel vehicles. This impedancemetric detection technology consists of a planar, single cell sensor design with various sensing electrode materials and yttria-stabilized zirconia (YSZ) as the electrolyte. No reference to ambient air is required. An impedance analysis method yields a signal that is proportional to the analyte gas concentration at a specific frequency. These sensors function by detecting the change in impedance caused by electron exchange in the redox reactions of NO x gases at the sensing electrodes. From the impedance data, the resulting shift in phase angle (∆Ө) is calculated, which can be calibrated to yield to the NO x concentration at low parts per million (ppm) levels.
Hamilton Sundstrand provides the aerospace industry with both original equipment and aftermarket ... more Hamilton Sundstrand provides the aerospace industry with both original equipment and aftermarket product support. This division of the United Technologies Corporation posted over $3 billion in revenues in 2001. Hamilton Sundstrand has manufacturing locations and service centers worldwide. In the wake of the events of September 11, 2002, the aerospace industry finds itself amid the largest downturn in the history of aviation. To cut costs and to streamline operations, Hamilton Sundstrand is introducing lean production techniques in their factories.
The baseline design of the Thermal Management System (TMS) of a parallel, hybrid electric aircraf... more The baseline design of the Thermal Management System (TMS) of a parallel, hybrid electric aircraft engine for a commercial, single aisle aircraft with batteries for energy storage has been completed. The Hybrid Electric Propulsion (HEP) system features a low spool motor to assist the propulsor, its attendant motor drive, propulsion batteries, and supplementary batteries to cover TMS electric loads during electric augmentation on takeoff and climb. The TMS further includes the heat loads sunk to engine oil including bearings, the fan drive system, and the accessory gearbox. The model was executed under hot day conditions (ISA + 15) over the mission sizing points when electric augmentation is active. REHEATS, a proprietary, object-oriented modeling tool created at the United Technologies Research Center, was used to model the TMS and find the solution with minimal fuel consumption. This study establishes a baseline for comparison of energy storage using batteries for future comparison. The results predict that the TMS of a HEP aircraft increases fuel consumption by 3.4% during takeoff, climb, and cruise.
Journal of Power Sources, Nov 1, 1998
... Just as Borup and Vanderborgh [29]found that their membrane electrode assemblies required a `... more ... Just as Borup and Vanderborgh [29]found that their membrane electrode assemblies required a `burn in' period consisting of several hours of operation before repeatable, stable performance was achieved in a single cell, all electrodes we tested in a half cell including smooth ...
AIAA Propulsion and Energy 2019 Forum, Aug 16, 2019
Alternative approaches and configurations for the Thermal Management System (TMS) of a parallel h... more Alternative approaches and configurations for the Thermal Management System (TMS) of a parallel hybrid electric propulsion system of a commercial single aisle aircraft have been compared to a baseline approach. A preferred configuration for the acquisition, transport and rejection of heat has been selected and a conceptual design has been completed. The Hybrid Electric Propulsion (HEP) system features a battery pack for energy storage, a low spool motor to assist the fan of a high bypass ratio geared turbofan, and an electric motor drive. The TMS services these HEP loads as well as the traditional engine heat loads including a high spool starter/generator, bearings (for shafts and fan drive system) and the accessory gearbox. The model was executed over a mission on hot day conditions (MIL-STD-210A). A proprietary, object-oriented modeling tool created at the United Technologies Research Center, REHEATS, was used to model the TMS and to optimize it for minimal fuel consumption. By separating the battery and motor drive cooling loops and by allowing battery thermal storage, ram air-cooled heat exchanger weight was reduced to one fifth of the baseline due to the higher temperature operation of the motor drive and due to colder air at the altitude where the battery heat exchanger was sized. The results predict that the TMS of a HEP aircraft increases fuel consumption due to the TMS weight, drag and power demand by approximately 49.0 lbm (~0.75%) per aircraft over a typical mission.
Proceedings, 1998
Polymer electrolyte fuel cell anodes containing noble metals, including either Pt, Pt-Ru, or Pt a... more Polymer electrolyte fuel cell anodes containing noble metals, including either Pt, Pt-Ru, or Pt and Sn particles were dispersed in a thin film o f polyaniline (PAni) on carbon cloth and tested as anodic material in a direct methanol fuel cell and polarization curves were recorded. Even if the performance o f these anodes remained in general inferior to that o f conventional electrodes, the curves obtained with Pt-Sn/PAni were encouraging, at least at low current densities.
Solid state electrochemical sensors that measure nitrogen oxides (NO x) in lean exhaust have been... more Solid state electrochemical sensors that measure nitrogen oxides (NO x) in lean exhaust have been investigated in order to help meet future on-board diagnostic (OBD) regulations for diesel vehicles. This impedancemetric detection technology consists of a planar, single cell sensor design with various sensing electrode materials and yttria-stabilized zirconia (YSZ) as the electrolyte. No reference to ambient air is required. An impedance analysis method yields a signal that is proportional to the analyte gas concentration at a specific frequency. These sensors function by detecting the change in impedance caused by electron exchange in the redox reactions of NO x gases at the sensing electrodes. From the impedance data, the resulting shift in phase angle (∆Ө) is calculated, which can be calibrated to yield to the NO x concentration at low parts per million (ppm) levels.
Hamilton Sundstrand provides the aerospace industry with both original equipment and aftermarket ... more Hamilton Sundstrand provides the aerospace industry with both original equipment and aftermarket product support. This division of the United Technologies Corporation posted over $3 billion in revenues in 2001. Hamilton Sundstrand has manufacturing locations and service centers worldwide. In the wake of the events of September 11, 2002, the aerospace industry finds itself amid the largest downturn in the history of aviation. To cut costs and to streamline operations, Hamilton Sundstrand is introducing lean production techniques in their factories. This thesis describes the implementation of lean manufacturing methods in the Windsor Locks, CT plant in the Air Management Systems Division. A description of the methodology used to introduce lean concepts as well as a comparison with the one advocated by MIT’s Lean Aerospace Initiative appears within. In addition, this thesis provides examples of the implementation of lean methods in the Heat Exchanger Core Assembly Area. As a part of th...
AIAA Propulsion and Energy 2020 Forum, 2020
Development of electric, hybrid and turboelectric propulsion technologies for electrified aircraf... more Development of electric, hybrid and turboelectric propulsion technologies for electrified aircraft propulsion system is essential for improving fuel consumption, reducing emissions and noise pollution, lowering maintenance costs and improving reliability of the air transportation systems. The future needs and key benefits of aircraft electrification has made it a highly persuaded common technology trend across the aerospace industry ranging from very large airplanes to small aircrafts, all alike. For very high power (20MW) propulsion system, with the inadequacies of current and near future state-of-the art of electric energy storage technologies, all electric aircraft solution faces enormous technology gaps that needs to be bridged. Advanced turbo-electric technology offers potential solutions towards successful realization of the benefits of electrification of aircrafts. However, this represent a grand challenge in many fronts to realize electric drivetrain (EDT) designs that would significantly improve fuel burn reduction, design flexibility, and operational improvements in next generation of aircrafts. This work focuses on the underlying technological elements to enable such high power turbo-electric aircraft. A preliminary study is carried out to find that to achieve the key benefits of electrifications, the ETD system efficiency has to be > 93% and the specific power density of the system is required to be > 7.5 kW/kg. Furthermore, it is found that that to achieve such system level performances, the EDT components is required to be ≥ 99% and with specific power densities > 40 kW/kg to achieve the 7.5 kW/kg target. These necessitates orders of magnitude of improvements at all technological fronts and requires radical improvement in design and integration methodologies. Major technologies and design trades for various components and system architectures are presented to provide guidelines and framework to address this grand challenge. Key results are provided to support the design study.
AIAA Propulsion and Energy 2020 Forum, 2020
Weight sensitivity studies were carried out on a Thermal Management System (TMS) of a parallel Hy... more Weight sensitivity studies were carried out on a Thermal Management System (TMS) of a parallel Hybrid Electric Propulsion (HEP) system of a commercial single aisle aircraft. The HEP system features a battery that feeds a Low Spool Motor (LSM) to assist the fan of a high bypass ratio geared turbofan. The first study gauged the impact of the Energy Storage, Conversion, & Distribution (ECS&D) system on the size of the Air Oil Cooler (AOC) and the Fuel Oil Cooler (FOC). The HEP system results in decreased FOC weight by 11% due to lower fuel flow at higher temperature due to the LSM and its heat load. Conversely, AOC weight increased by 32% also due to the higher heat load. A second study examines the effect of efficiency of the battery and motor drive on the TMS. Increases in efficiency of the battery from 95% to 96% and the motor drive (MD) from 96% to 98% decrease the weights of their Ram air Coolant Coolers (RCC) by 26% and 38%, respectively, as well as the heat sink air flow through them. Lastly, the altitude at which the Battery ram air Cooled Cooler (Bat RCC) was sized to reject the full heat load on a hot day (8 kft vs 20 kft) was examined. A TMS weight decrease in excess of 50 lbs. is possible for the 20 kft case provided that batteries are sufficiently pre-cooled below ambient temperature prior to take-off.
Solid state electrochemical sensors that measure nitrogen oxides (NO x) in lean exhaust have been... more Solid state electrochemical sensors that measure nitrogen oxides (NO x) in lean exhaust have been investigated in order to help meet future on-board diagnostic (OBD) regulations for diesel vehicles. This impedancemetric detection technology consists of a planar, single cell sensor design with various sensing electrode materials and yttria-stabilized zirconia (YSZ) as the electrolyte. No reference to ambient air is required. An impedance analysis method yields a signal that is proportional to the analyte gas concentration at a specific frequency. These sensors function by detecting the change in impedance caused by electron exchange in the redox reactions of NO x gases at the sensing electrodes. From the impedance data, the resulting shift in phase angle (∆Ө) is calculated, which can be calibrated to yield to the NO x concentration at low parts per million (ppm) levels.
Journal of Solid State Electrochemistry, Jun 23, 2012
Sensors that detect NO x by a change in impedance were fabricated with gold wire electrodes and Y... more Sensors that detect NO x by a change in impedance were fabricated with gold wire electrodes and YSZ electrolyte. The effects of temperature, NO x species, flow rate, and cross sensitivity to O 2 were quantified and evaluated. The largest phase angle shift due to NO x was found at the lowest temperature investigated (600°C). Linear relationships existed between the shift in phase angle and NO x quantity up to 100 ppm. NO 2 evoked a larger response than NO at 650°C. A reversible poisoning effect was observed following exposure to NO 2. The sensing impedance signal at 10 Hz was invariant to total flow rate. Cross sensitivity to O 2 was noted. Although O 2 evoked a much smaller response than NO x , the larger quantity of O 2 of lean exhaust necessitated compensation. Keywords Impedancemetric NO x sensor. Electrochemical impedance spectroscopy (EIS). Yttria-stabilized zirconia (YSZ) Abbreviations EIS Electrochemical impedance spectroscopy NO x Nitrogen oxides YSZ Yttria-stabilized zirconia
Ionics, Jan 13, 2011
The intent of this paper is to establish the state of the art of impedance-based gas sensors. Thi... more The intent of this paper is to establish the state of the art of impedance-based gas sensors. This sensor type holds promise for accurate detection of gaseous species at single parts per million and below. Impedance-based sensors do not require reference air to function, but do require calibration. Progress in the development of impedancemetric sensors for the detection of NO x , H 2 O, hydrocarbons, and CO is reviewed. Sensing electrodes typically consist of a noble metal or a metal oxide. YSZ is the preferred electrolyte material. Counter electrodes of Pt were common in asymmetric cells. These sensors typically operate at 500-700°C and are interrogated at 10 Hz or less. Selectivity of these sensors remains a challenge especially in lean environments. Stability is an infrequently discussed yet important concern. Equivalent circuit analysis has shed light on various detection mechanisms. The impedance changes due to analyte gases are exhibited in parameters that represent the low frequency behavior of the electrochemical system. Although the search for a detailed mechanism continues, the change in impedance due to a specific gas is generally attributed to transport processes such as adsorption and charge transfer.
This work presents a novel scheme for the use of an oxygen sensor operating in dynamic engine con... more This work presents a novel scheme for the use of an oxygen sensor operating in dynamic engine conditions. Our modeling and experimental work show that a solid state, single cell, amperometric oxygen sensor located inside the cylinder of a lean direct injection engine produces a signal that provides different information depending on the stroke. During the intake stroke, the sensor’s signal is proportional to the partial pressure of oxygen, facilitating exhaust gas recirculation. During the compression stroke of a diesel engine prior to fuel injection, the sensor’s output indicates the cylinder pressure, which is useful for control and diagnostic purposes. The signal during the power stroke confirms combustion. During the exhaust stroke, the sensor’s signal indicates the oxygen quantity after combustion. Our model of engine and sensor operation simulates the changes in air properties including temperature, pressure, and oxygen concentration over the entire four strokes of the diesel cycle; these parameters affect the diffusivity of oxygen and the signal output. The model describes a sensor signal limited by diffusion or electrolytic conductivity depending on electrode design parameters (dimensions, porosity, tortuosity, etc). Knowledge of the sensor temperature and the engine crank angle are required in order to evaluate the signal. Experimental results confirm the pressure dependence of the oxygen sensor’s output signal when using air as the analyte fluid.Copyright © 2008 by ASME
Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, Nov 28, 2010
Conventional surface micromachining techniques including photolithography and both wet and dry et... more Conventional surface micromachining techniques including photolithography and both wet and dry etching have been directly applied to an unfired sheet of yttria-stabilized zirconia ceramic material. Reversible bonding methods were investigated for affixing unfired ceramic samples to silicon handle wafers in order to perform photolithography. Three types of photoresist were investigated. Thin film photoresist allowed a line-width feature size of 8 lm to be obtained. Thick film photoresist exhibited a coverage gradient after being spun on. Chemical etching was successfully performed isotropically with concentrated hydrofluoric acid. A dry thick film resist applied by lamination provided coverage during plasma etching. Neither an oxygen plasma nor a mixture of sulfur hexafluoride and oxygen plasma proved successful at etching the unfired ceramic. Embossing was performed on the meso-scale with feature shrinkage of approximately 45% after sintering. Abbreviations HTCC High temperature cofired ceramic LTCC Low temperature cofired ceramic R a Average surface roughness YSZ yttria-stabilized zirconia
Four single cell impedancemetric NOx sensors were fabricated in the context of a two level, half ... more Four single cell impedancemetric NOx sensors were fabricated in the context of a two level, half fractional factorial experimental design (2III 3-1 ) to determine the effect of design features on sensitivity to NO or NO2. Three design factors were varied: number of working electrode sensing wires, electrolyte thickness, and the distance between sensing wires. Sensing ability was measured by performing electrochemical impedance spectroscopy and calculating the phase angle difference at 10 Hz for 50 ppm NO or NO2 in 10% oxygen. As determined by ANOVA, the most significant effect was electrolyte thickness for NO sensing. One sensor investigated in depth showed a linear relationship between phase angle difference and NO at low concentration, insensitivity to total flow rate, and the larger sensitivity to NOx species than O2 by several orders of magnitude. A larger response for NO2 compared to NO was found. At 10 5 Hz, phase angles were linearly related to temperature, independent of gas...
Volume 3: Combustion Science and Engineering, 2008
This work presents a novel scheme for the use of an oxygen sensor operating in dynamic engine con... more This work presents a novel scheme for the use of an oxygen sensor operating in dynamic engine conditions. Our modeling and experimental work show that a solid state, single cell, amperometric oxygen sensor located inside the cylinder of a lean direct injection engine produces a signal that provides different information depending on the stroke. During the intake stroke, the sensor’s signal is proportional to the partial pressure of oxygen, facilitating exhaust gas recirculation. During the compression stroke of a diesel engine prior to fuel injection, the sensor’s output indicates the cylinder pressure, which is useful for control and diagnostic purposes. The signal during the power stroke confirms combustion. During the exhaust stroke, the sensor’s signal indicates the oxygen quantity after combustion. Our model of engine and sensor operation simulates the changes in air properties including temperature, pressure, and oxygen concentration over the entire four strokes of the diesel cycle; these parameters affect the diffusivity of oxygen and the signal output. The model describes a sensor signal limited by diffusion or electrolytic conductivity depending on electrode design parameters (dimensions, porosity, tortuosity, etc). Knowledge of the sensor temperature and the engine crank angle are required in order to evaluate the signal. Experimental results confirm the pressure dependence of the oxygen sensor’s output signal when using air as the analyte fluid.Copyright © 2008 by ASME
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Papers by Jonathan Rhéaume