Accurate, accessible methods for monitoring and evaluation of improved cookstoves are necessary to optimize designs, quantify impacts, and ensure programmatic success. Despite recent advances in cookstove monitoring technologies, there are no existing devices that autonomously measure fuel use in a household over time and this important metric continues to rely on in-person visits to conduct measurements by hand. To address this need, researchers at Oregon State University and Waltech Systems have developed the Fuel, Usage, and Emissions Logger (FUEL), an integrated sensor platform that quantifies fuel consumption and cookstove use by monitoring the mass of the household’s fuel supply with a load cell and the cookstove body temperature with a thermocouple. Following a proof-of-concept study of five prototypes in Honduras, a pilot study of one hundred prototypes was conducted in the Apac District of northern Uganda for one month. The results were used to evaluate user engagement with the system, verify technical performance, and develop algorithms to quantify fuel consumption and stove usage over time. Due to external hardware malfunctions, 31% of the deployed FUEL sensors did not record data. However, results from the remaining 69% of sensors indicated that 82% of households used the sensor consistently for a cumulative 2188 days. Preliminary results report an average daily fuel consumption of 6.3 ± 1.9 kg across households. Detailed analysis algorithms are still under development. With higher quality external hardware, it is expected that FUEL will perform as anticipated, providing long-term, quantitative data on cookstove adoption, fuel consumption, and emissions.

This paper describes the experimental analysis of the heat transfer rate within an internal passage of a typical gas turbine blade using varied internal geometries. This method of alteration, using rib turbulator’s within the serpentine cooling passages of a hollow turbine blade, has proven to drastically cool turbine blades more significantly than a smooth channel alone. Our emphasis is to determine which rib geometry will yield the highest heat transfer rate, which was examined in the form of a comparison between theoretical to experimental Nusselt numbers. For testing purposes, an enclosed 2 in. × 2 in. square Plexiglas channel was constructed to model an internal cooling passage within a turbine blade. Silicon heat strips, wrapped in copper foil, were placed on the bottom surface of the channel to ensure even heat distribution throughout. To measure internal surface temperatures, thermocouples were placed on the surface of heat plate as well as in the opening of the channel throughout. The four different rib geometries which were individually wrapped in copper foil were then placed on top of the heating element. To compare the rib geometry results with a control, a test was run with no ribs. To simulate turbulent air flow through the channel, a blower supplied velocities of 23.88 m/s and 27.86 m/s. These velocities yielded a Reynolds number ranging between 70,000 and 90,000. Final results were found in the form of the experimental Nusselt number divided by the theoretical Nusselt number, a standard when comparing surface heat transfer rates. The 60 degree staggered arrow geometry pointing away from the inlet and outlet (geometry 4) proved to create the highest heat transfer rate through the way it produced turbulent air flow. The average Nusselt number of this design was found to be 718.2 and 868.3 for 23.88 and 27.86 m/s respectively. From the calculated data it was found that higher Nusselt numbers were more prone to occur in higher air velocities.

The modelling of the friction interfaces has received much attention in recent years from the aerospace industry. In order to obtain reliable prediction of the nonlinear dynamic behaviour of the disc and blades in the aerospace engine the friction forces at interfaces, such as in under-platform dampers, blade and fir tree roots or shrouds, must be modelled accurately. Two contact parameters, namely the contact stiffness and the coefficient of friction, are sufficient to model, with good accuracy, the friction contact. The contact parameters are obtained experimentally, and are of interest for the designer only if representative of the operational environment of the engine. To pursue this aim a test rig has been designed to perform experiments in a wide range of temperatures, with different combinations of normal and tangential load, frequencies and mating materials, representative of the real operating condition of the engine. Most of the rigs found in literature perform most likely point contact even if the two bodies have plane mating surfaces. The design of a real plane-on-plane contact test rig is not an easy task but despite the difficulty a solution was found in the design shown in this work. The core of the rig is a tilting mechanism enabling one surface to lies down on the other so that the plane-on-plane contact is achieved, at least within the flatness geometrical tolerance of the surfaces. The results of the experiments are the hysteresis loops, namely the tangential contact force against the relative displacement, from which the contact parameters can be calculated. Measurements of displacements are taken very close to the actual contact area and are performed by means of two laser interferometers. Localized heating is achieved by means of an induction heating machine while a thermocouple measures the temperature at points close to the contact area.

Friction stir welding is a patented joining process invented in 1991 at The Welding Institute in Cambridge, UK, and further developed to the stage suitable for production. In this process, a wear resistant rotating tool is used to join sheet and plate with different materials such as aluminum, copper, lead, magnesium, zinc, and titanium. This work studies the thermal characteristics of this process and provides a modeling technique based on Neural Network that can be used for real-time control. A thermal feed-back control method is presented to control the process. Using some thermal modeling for the heat distribution during friction stir welding process, this paper displays the complexity of obtaining an accurate design for the thermal feed back control. A three-dimensional transient heat transfer model is developed here for a sequential joining process (Friction Stir Welding-FSW) applied on aluminum parts. A neural network is created based on a set of experiments to predict the spatial and temporal variations in the temperature over the weld seam for different set of input variables. The model includes the dynamic and friction behavior of the rotating spindle and the thermal behaviors of the weld components involved. The significance of this modeling approach is that it captures the movement of the spindle, simulating a sequential joining process along a continuous weld seam. The modeling results are compared with experimental data obtained by thermocouples and infrared camera, and accurately predict the trend of variations in weld temperature. A fuzzy-logic based controller is proposed to regulate the FSW process parameters to maintain the weld temperature within the margin required to ensure the weld quality. This modeling and control system can have applications in manufacturing aluminum parts in automotive and aerospace industry.

Condition monitoring of bearings has been a major research topic for more than five decades. To validate and improve the condition monitoring techniques, this paper focuses on the development of an innovative and versatile bearing test rig. The rig allows applying a fully controlled multi-axial static and dynamic load on different types and sizes of bearings. Easy adjustment to mount bearings with different inner diameter, outer diameter and width is possible, without compromising on performance. Furthermore, the behaviour of the bearing is monitored by accelerometers, proximity probes and thermocouples. During the design of the rig, several techniques were applied to ensure clean measurements, with maximum repeatability, and to reduce errors due to temperature variations. Finally, introducing an additional dynamic force on the bearing makes it possible to load the bearing as if it were built into a real machine, for example a gearbox. At the time this paper is written, results of the test rig were not yet available. However, the authors expect to be able to report on the first test results during the conference.

A three-dimensional transient heat transfer model is developed for a sequential joining process (resistance welding) applied on thermoplastic composites. This process involves with moving a voltage source along a heating element that conducts the power throughout a resistive mesh, generating heat and melts and bounds two composite surfaces. The model developed here is used to predict the spatial and temporal variations in the current and temperature over the weld seam for different set of input variables. The model integrates both the resistive and thermal behaviours of components involved. The significance of this modeling approach is that it captures the movement of the electrical connection, simulating a sequential joining process along a continuous weld seam. The modeling results are compared with experimental data obtained by thermocouples and infrared camera, and accurately predict the trend of variations in weld temperature.

The experimental knowledge about medium lubricated journal bearings (e.g. diesel-oil lubricated sliding bearings in fuel-injection systems) is far too small in order to confirm the different hypotheses of the actual simulation models. The study of such components implicates very restrictive requirements on security against explosion, exact measurement of the friction torque and so on. A new test bench design to meet these requirements is presented, allowing a system-conform study of the components. For a high resolution of the temperature repartition in the smearing gap, thin film sensors, which have allowed the verifications experiments in the field of the Elastohydrodynamic-lubrication (EHL) are being enhanced. Beside a higher wear resistance, a reduction of the sensor size is an important requirement for the new sensor generation, allowing the resolution of local phenomena in the mixed lubrication. For the electrical isolation and wear protection of the new sensors developed at the Institute of Product Development of the University of Karlsruhe (TH) (IPEK), diamond like carbon (DLC) coatings are used. For the fulfillment of the requirements on the size of the sensors, a new concept of micro thermocouples is presented.

Frictional heating from rolling and sliding contacts of gear teeth is of extreme importance for monitoring the health of a gear transmission under its continuing operation. The surface temperature holds the critical information about a gear’s health condition. A new power circulating gear test rig with a multichannel computer data acquisition system has been built to develop various sensor technologies for surface temperature evaluation of gear teeth. In this paper, the surface temperature monitoring of gear tooth will be presented by using miniature thermocouples. Five miniature type-K thermocouples of 125 μm in diameter have been embedded underneath the tooth surface of a spur gear, and real-time surface temperature variations from a wide range of operating conditions were measured. The various effects of load, rotating speed, and meshing point on the surface temperature are discussed. The results attained in this study indicate that the maximum temperature rise occurs on the dedendum, close to the dedendum circle, and the maximum surface temperature difference at the various contact points along the tooth profile was 13°C. Among the various temperature monitoring techniques, the thermocouple is a very reliable and practical mean for gear health monitoring.

This paper describes the effect of traction oil on the power loss of spur gear drive. In this study, we measured the power loss of super gear drive using several traction oils. We separated the power loss into gear friction loss and oil churning loss. Furthermore, we measured the surface temperature on the gear tooth by the dynamic thermocouple method, and observed the lubrication condition between meshing teeth by the electrical resistance method. Then, we investigated the relationships between the power loss of the gear drive lubricated with the traction oil, the surface temperature on the gear tooth, and the lubrication condition.

The objective of this study was to investigate the present cooling system of a lawn mower tractor engine and come out with an idea to modify the system. The test section was created to measure the velocity and temperature around the engine compartment. Velocity and temperature measurements were collected at several different locations around the engine. To accomplish this, several Pressure transducers along with Pitot tubes and Thermocouples were placed at several predetermined locations based on their assumed experimental importance. Since the experiment was run in a laboratory setting, the Combustion products of the engine were vented to the environment through a venting system via a stainless steel hose. This hose was constructed to attach to both the tractor muffler and the building venting. Then, the instrumentation had to be sized and selected such that the data could be easily acquired and recorded. Next, the necessary data was collected using the selected instrumentation while running the engine in the laboratory space. This data was used to produce an accurate computer model for simulation and to compare several different design adaptations. Based on experimental and computational data, it is noticed that the engine compartment was exhausting hot air that was causing discomfort to the operator and potential harm to the area near their feet. Some modifications were recommended, such as the baffling system, fan system, and grill alterations as an attempt to alter the airflow characteristics of the engine compartment to redirect the hot air away from operator’s feet.

This paper describes an effective, but simple, technique using a computer interface for control, data acquisition, and processing of a heat pump laboratory experiment. A water-to-air heat pump that allows comfort cooling and heating from a single source is used as an experiment and will be incorporated in a Mechanical Engineering Laboratory Course. Presently, the source is the city water. Plans are in place to use a ground source that provides a relatively constant temperature water supply, as low as 45°F. This well-instrumented laboratory teaching equipment allows students to measure temperatures, pressures, flow rate, and power input and then calculate the coefficient of performance of the system and the efficiency of the compressor both manually and automatically. A self-contained Windows-based data collection and analysis system has been developed for automating all the manual functions of a WPH-J Series Water-to-Air Heat Pump from Heat Controller, Inc. This system uses a data acquisition board to read the voltage signals corresponding to 9 T-type thermocouples, three pressure gauges, and compressor supplied power. The data acquisition and control software written in Visual Basic 6 uses 32-bit libraries to control the operation mode, read the thermocouples’ voltages, water flow rate, compressor’s input and output pressure, and supplied power.