No description available.

An upgrade in technology has changed the way audio feedback is given to fighter pilots when using short range infrared guided air-to-air missiles. Audio feedback from the missile tracking system is one tool used by pilots to assess the probability of success before launching a missile. After launch the missile is completely autonomous. / For many decades previous missiles with analogue signal processing used an enhanced by-product of their signal processing to produce an audio tone for the pilot. The volume and quality of this tone provided insight on the strength and quality of the target signal as processed by the missile. New missiles use imaging systems with digital signal processing and there is no similar audio frequency signal produced. However there is a great deal more information available and a much more capable processing system. This allows the missile designer the opportunity to present the pilot with an enormous amount of information, or none at all. / During the course of this research project missile experts have been consulted to ascertain what information could be encoded in the missile tone. Fighter pilots have been interviewed and surveyed to determine what information they desire to have presented and how it should be presented. The staff of the RAAF F/A-18 simulator facility have been consulted and they have provided advice on the F/A-18 audio environment. Finally several data mappings and tone schemes have been prepared and tested to assess the efficiency of data flow from the missile to the pilot via the audio interface. A brief investigation into the potential for confusion and masking has also been carried out. / As a result of this work, two cost effective tone schemes and one more expensive scheme have been produced and tested. Acceptable performance has been proven in a laboratory setting. The two cost effective schemes have been ranked in order of preference by a group of fighter pilots and are ready for implementation. The third scheme has been kept as a reference for possible longer-term upgrades. / Thesis (MEng(ElectronicsEngineering))--University of South Australia, 2005.

An upgrade in technology has changed the way audio feedback is given to fighter pilots when using short range infrared guided air-to-air missiles. Audio feedback from the missile tracking system is one tool used by pilots to assess the probability of success before launching a missile. After launch the missile is completely autonomous. / For many decades previous missiles with analogue signal processing used an enhanced by-product of their signal processing to produce an audio tone for the pilot. The volume and quality of this tone provided insight on the strength and quality of the target signal as processed by the missile. New missiles use imaging systems with digital signal processing and there is no similar audio frequency signal produced. However there is a great deal more information available and a much more capable processing system. This allows the missile designer the opportunity to present the pilot with an enormous amount of information, or none at all. / During the course of this research project missile experts have been consulted to ascertain what information could be encoded in the missile tone. Fighter pilots have been interviewed and surveyed to determine what information they desire to have presented and how it should be presented. The staff of the RAAF F/A-18 simulator facility have been consulted and they have provided advice on the F/A-18 audio environment. Finally several data mappings and tone schemes have been prepared and tested to assess the efficiency of data flow from the missile to the pilot via the audio interface. A brief investigation into the potential for confusion and masking has also been carried out. / As a result of this work, two cost effective tone schemes and one more expensive scheme have been produced and tested. Acceptable performance has been proven in a laboratory setting. The two cost effective schemes have been ranked in order of preference by a group of fighter pilots and are ready for implementation. The third scheme has been kept as a reference for possible longer-term upgrades. / Thesis (MEng(ElectronicsEngineering))--University of South Australia, 2005.

A run-around membrane energy exchanger (RAMEE) is a novel energy exchanger that is capable of transferring both heat and moisture, which can significantly reduce the energy required to condition outdoor ventilation air. The RAMEE uses a liquid desiccant to transfer both heat and moisture between two remote air streams, making it appropriate for many applications, including building HVAC retro-fits. Both initial system start-up and changing outdoor conditions require time for the desiccant to undergo changes in both temperature and concentration, and can cause significant transient delays in system performance. Under some conditions, these transients may be beneficial by increasing the system performance. However under some conditions, the transient delays can cause a substantial decrease in performance.<p> This thesis focuses on the development of control strategies that can be used to reduce unwanted transient delays. In order to develop these control strategies, the performance of a RAMEE is first investigated using both experimental and numerical methods. The transient numerical and experimental effectiveness results show satisfactory agreement, with a maximum root mean squared error of 10%. Both the numerical and experimental data show that a long transient time of several hours, or even several days, can occur upon initial system start-up.<p> The numerical model is used to investigate several control strategies to reduce unwanted transient delays. The control strategies investigated are: solution and air flow control, air flow bypass, solution temperature control, and solution concentration control. The solution and air flow control are shown to reduced the start-up transient time by up to 11%, but require either a reduction in air flow or an increase in solution pumping costs. Air flow bypass proves to be a better option which provides a 16% reduction in transient time, and only requires that a bypass damper be provided for each exchanger. Solution temperature control is capable of essentially eliminating the thermal transient time (time required for the solution to reach operating temperature), but the thermal transient time is found to be a minor contributor to the overall transient time (time required for the solution to reach operating temperature and concentration) when the initial concentration of the solution is different than the steady-state concentration. When thermal and moisture transients exist, total transient times may be over 18 days. A practical temperature and concentration control strategy is developed, which can reduce transient delays by over 90% and increase performance during variable outdoor weather conditions.

Hybrid testing is an emerging technique for system emulation that uses a transfer system composed of actuators and sensors to couple physical tests of a critical component or substructure to a numerical simulation of the remainder of a system and its complete operating environment. The realisation of modern real-time hybrid tests for multi-body contact-impact problems often proves infeasible due to (i) hardware with bandwidth limitations and (ii) the unavailability of control schemes that provide satisfactory force and position tracking in the presence of sharp non-linearities or discontinuities. Where this is the case, the possibility of employing a pseudo-dynamic technique remains, enabling tests to be conducted on an enlarged time scale thus relaxing bothbandwidth and response time constraints and providing inherent loop stability. Exploiting the pseudo-dynamic technique, this thesis presents the development of Robotic Pseudo-Dynamic Testing (RPsDT), a dedicated method that specifically targets the realisation of hybrid tests for multi-body contact-impact problems using commercial off- the shelve (COTS) industrial robotic manipulators. The RPsDT method is evaluated in on-ground studies of air-to-air refuelling (AAR) maneuvers with probe-hose-drogue systems where the critical contact and coupling phase is tested pseudo-dynamicallywith full-scale refuelling hardware while the flight regime is emulated in simulation. It is shown that the RPsDT method can faithfully reproduce the dominant contact impact phenomena between probe and drogue while minor discrepancies result from the absence of rate-dependant damping in the force feedback measurements. In combination with full-speed robot controlled contact tests, reliable estimates for impact forces, strain distributions and drogue responses to off-centre hits are obtained providing extensive improvements over current predictive capabilities for the in-flight behaviour of refuelling hardware and it is concluded that the technique shows great promise for industrial applications.

No description available.

Rotary air-to-air energy exchangers (also called energy wheels) transfer both heat and moisture between supply and exhaust airstreams in buildings. In this thesis, it is hypothesized that the transient step response characteristics of an energy wheel are uniquely related to the steady-state cyclic response of the wheel. The primary objective of this research is to study the transient response of a humidity/temperature sensor and measure energy wheel performance with a new test procedure that uses only transient response characteristics. In this thesis, the transient characteristics of a humidity/temperature sensor and an energy wheel to a step change in relative humidity and temperature are investigated through two types of measurements. One test uses a small airflow, at controlled temperature and humidity conditions, passing through a small section of a porous wheel while measuring the outlet conditions after the inlet conditions are suddenly changed. For a step input, it is shown that the outlet humidity/temperature sensor data correlate with an exponential function with two time constants. Since the transient response characteristics of the humidity/temperature sensor must be known to predict the response of the wheel alone, a second test is required that is similar to the first test except that the wheel is removed. This test is used to obtain the transient response of the sensor alone. Data from these tests show that both the sensor and the sensor plus wheel have two sets of two time constants. An analysis is presented to determine the transient response of the wheel alone using the correlated properties of the sensor alone and the sensor with a wheel upstream. The challenge undertaken in this research was the development of a more flexible, lower cost test facility than that presented in ASHRAE Standard 84-1991(Method of Testing Air-to-Air Heat Exchangers). In future work, this new laboratory experimental test facility should be adapted to test most types of energy wheels. The configuration allows a wide range of mass flow rates, inlet supply air temperatures and relative humidities. Uncertainty analysis is used for each transient test for the sensors and air-to-air energy wheels to specify the sensor and wheel plus sensor characteristics. This uncertainty analysis shows that accurate sensor calibration under equilibrium conditions and the start time for the humidity sensor step change is crucial to achieve low uncertainties in the transient behaviour of sensor and energy wheels. Knowing the uncertainty in the characteristics of the sensors and the wheel plus sensors the uncertainty in the transient response of the wheel alone is predicted. The first time constant of the humidity sensor is found to be about 3 seconds, while the second time constant is found to be about 100 seconds. It is found that the predicted response of the wheel alone gives time constants that are about 6 seconds and 140 seconds. Other researchers can use this information presented in this thesis to estimate the effectiveness of an energy wheel.

Rotary air-to-air energy exchangers (also called energy wheels) transfer both heat and moisture between supply and exhaust airstreams in buildings. In this thesis, it is hypothesized that the transient step response characteristics of an energy wheel are uniquely related to the steady-state cyclic response of the wheel. The primary objective of this research is to study the transient response of a humidity/temperature sensor and measure energy wheel performance with a new test procedure that uses only transient response characteristics. In this thesis, the transient characteristics of a humidity/temperature sensor and an energy wheel to a step change in relative humidity and temperature are investigated through two types of measurements. One test uses a small airflow, at controlled temperature and humidity conditions, passing through a small section of a porous wheel while measuring the outlet conditions after the inlet conditions are suddenly changed. For a step input, it is shown that the outlet humidity/temperature sensor data correlate with an exponential function with two time constants. Since the transient response characteristics of the humidity/temperature sensor must be known to predict the response of the wheel alone, a second test is required that is similar to the first test except that the wheel is removed. This test is used to obtain the transient response of the sensor alone. Data from these tests show that both the sensor and the sensor plus wheel have two sets of two time constants. An analysis is presented to determine the transient response of the wheel alone using the correlated properties of the sensor alone and the sensor with a wheel upstream. The challenge undertaken in this research was the development of a more flexible, lower cost test facility than that presented in ASHRAE Standard 84-1991(Method of Testing Air-to-Air Heat Exchangers). In future work, this new laboratory experimental test facility should be adapted to test most types of energy wheels. The configuration allows a wide range of mass flow rates, inlet supply air temperatures and relative humidities. Uncertainty analysis is used for each transient test for the sensors and air-to-air energy wheels to specify the sensor and wheel plus sensor characteristics. This uncertainty analysis shows that accurate sensor calibration under equilibrium conditions and the start time for the humidity sensor step change is crucial to achieve low uncertainties in the transient behaviour of sensor and energy wheels. Knowing the uncertainty in the characteristics of the sensors and the wheel plus sensors the uncertainty in the transient response of the wheel alone is predicted. The first time constant of the humidity sensor is found to be about 3 seconds, while the second time constant is found to be about 100 seconds. It is found that the predicted response of the wheel alone gives time constants that are about 6 seconds and 140 seconds. Other researchers can use this information presented in this thesis to estimate the effectiveness of an energy wheel.

As alternative fuels are becoming more common, technologies need to adjust to them. Natural gas is one of the alternative fuels that has grown during the latest years in the transport sector. Natural gas consists of around 97 % methane and is the cleanest fossil fuel. The use of natural gas can make it easier to transition to biogas as it has equivalent properties. Today Scania CV AB's trucks fuelled by natural gas are using auxiliary cabin heaters driven by diesel. This means that the natural gas trucks have two fuels on-board the truck. The goal of this project is to find a concept to eliminate the diesel fuel and replace it with an auxiliary cabin heater driven by another energy source. It will improve the heating solution and make it superior from an environmental perspective. The result of the project lead to a short-term solution with an auxiliary heater fuelled by natural gas. A long-term solution is to have a cooperation with a manufacturer to develop a better natural gas auxiliary heater that fulfils more of the requirements in the technical specification. An experiment plan is devised to test parameters out of reach of the project.

Aujourd'hui, la pompe à chaleur (PAC) est largement utilisée pour les applications de chauffage du bâtiment en raison de ses bonnes performances énergétiques. Elle est même considérée comme une source d'énergie renouvelable et, selon la Directive Européenne 2009/28/CE, la part «renouvelable» de l'énergie produite doit être calculée à partir de la performance annuelle. Il est donc important d'être à même de mesurer cette dernière. Or, il n'existe pas, pour les PAC air/air, de méthode fiable et simple permettant de mesurer la performance chez le client pendant une saison.Dans ce contexte, la thèse propose deux méthodes in situ qui répondent à ce besoin. La première est basée sur des mesures non-intrusives des propriétés du fluide frigorigène. Elle utilise le bilan énergétique du compresseur pour déterminer le débit du fluide. La deuxième, fondée sur les mesures côté air, utilise un ensemble de capteurs à fil chaud afin de mesurer le débit et les températures d'air.La thèse développe également une méthode de mesure intrusive du fluide frigorigène, qui n'est pas adaptée aux conditions in situ mais sert de référence pour valider les deux méthodes in situ. Les résultats expérimentaux montrent que la méthode de référence est précise non seulement en conditions stabilisées mais également en fonctionnement dynamique (y compris lors des dégivrages).La validation des deux méthodes in situ a été réalisée par une campagne d'essais spécifique en laboratoire. Une suite intéressante de la thèse consistera à intégrer la méthode non intrusive côté frigorigène directement dans l'équipement de mesure et d'affichage de la PAC. / Today, heat pumps (HP) are widely used as heating systems in building thanks to their high energy efficiency. They are even considered as a source of renewable energy and, according to the EU Directive 2009/28/EC, the amount of renewable energy has to be calculated from the annual performance. Therefore, it is important to be able to measure the annual performance. However, concerning the air-to-air HP there is no reliable and simple method which allows measuring the performance in situ during at least a season.In this context, the thesis proposes two in situ methods that could fill this gap. The first one is based on non-intrusive measurements on refrigerant side. It uses a compressor energy balance to determine the flow rate. The second one, based on air measurements, uses a distribution of hot-wire sensors to determine the air flow rate and temperatures.The thesis also develops an intrusive refrigerant method, which is not necessarily adapted for in situ conditions but can be used as a reference to validate the in situ methods. The experimental results show that the reference method is accurate both in stationary conditions and in dynamic operations (including during defrosting period).The validation of the in situ methods was performed by a specific test campaign in laboratory. As a perspective, the thesis makes it possible to develop on-board measurement methods using non-intrusive refrigerant sensors, providing an opportunity for manufacturers to display the in situ performance in real time.