A novel exhaust heat recovery system to reduce fuel consumption

Internal combustion engines release about 1/3 of the energy bound in the fuel as exhaust waste gas energy and another 1/3 energy is wasted through heat transfer into the ambient. On the other hand losses through friction are the third largest root cause for energy loss in internal combustion engines. During city driving frictional losses can be of the same size as the effective work, and during cold start these losses are even bigger. Therefore it is obvious to utilise wasted exhaust energy to warm up the engine oil directly. Frictional losses of any engine can be reduced during part load. Sensitivity analyses have been conducted for different concepts that utilise exhaust energy to reduce engine viscosity and friction. For a new system with an exhaust gas/oil heat exchanger the following benefits have been demonstrated:&bull; Fuel consumption reductions of over 7% measured as an average over 5 NEDC testscompared to the standard system configuration.&bull; Significant reductions in exhaust emissions, mainly CO and NOx have been achieved&bull; Significantly higher oil temperatures during cold start indicate large potential toreduce engine wear through reduced water condensation in the crankcase&bull; Fuel consumption reductions of further 3.3% to 4.6% compared to the 7% measuredover the NEDC test can be expected under real world customer usage conditions atlower ambient temperatures.Oil temperature measurements and analysis resulted in the idea of a novel system with further potential to reduce fuel consumption. This Oil Viscosity Energy Recovery System (OVER 7&trade;) consists of 3 key features that add significant synergies if combined in a certain way: an oil warm up circuit/bypass, including oil pressure control and Exhaust Gas/Oil Heat Exchanger. The system separates the thermal inertias of the oil in the engine galleries and the oil pan, reduces hydraulic pumping losses, increases the heat transfer from the cylinder head to the oil, and utilises the exhaust heat to reduce oil friction.The project demonstrated that sensitivity analysis is an important tool for the evaluation of different concepts. Especially for new concepts that include transient heat transfer such a qualitative approach in combination with accurate experiments and measurements can be faster and more efficient in leading to the desired improvements compared to time consuming detailed simulations.<br /

"Tomorrow\u27s car" : Deakin Universities new cross vehicle that combines the best of 2 worlds

Motorbike riders are 34-times more likely to die in a crash compared to car drivers per km travelled (1). Such safety risks together with special skill requirements for the driver and much lower comfort compared to normal cars are the main reasons why motorbikes represent only a fraction of all vehicle sales in developed countries. Deakin University is developing a revolutionary cross-over fun vehicle with ultra low fuel consumption and emissions. This new vehicle generation combines the best of two worlds: the fun to drive, low cost, and small size of a scooter together with the safety, comfort and easiness to operate of a car. The result is a vehicle that is more fuel efficient than most cars or even scooters.Various tilting cross over vehicles have been presented over the last decade that were trying to automate the tilting control of narrow vehicles to make them safer. Examples of these concepts are the Carver, Clever and in some way also the MP3 scooter from Piaggio. The problem with fully enclosed concepts like the Carver or Clever is that they require very complex and therefore also expensive tilting control systems so that the vehicles are not price competitive compared to low cost micro cars or even normal small cars. The MP3 on the other hand comes with a tilting control system which is only semi automatic so that typical car advantages - comprehensive safety features like crush zones, roll over protection, air bags, safety belts or comfort features like full weather protection including heating and cooling &ndash; can not be provided.Deakin&rsquo;s approach is quite different to the above mentioned concepts. The requirements were derived based on two different investigations: The first step was a critical evaluation of social trends and the second step was an in-depth benchmarking study of existing concepts which identified the typical strengths and weaknesses of these concepts. In a critical next step a new concept was created that addresses most of the weaknesses of existing tilting three-wheelers in a holistic approach by setting clear priority rankings for the vehicle targets, based on current trends. The priorities were set in the following order: Safety, Affordability, Fun and Efficiency (SAFE).The key feature that enables an enclosed tilting vehicle is a fully automatic tilting control system. With an automatic tilting control system the driver does not need to put the feet on the ground to balance the vehicle when he stops, so the vehicle can be built with a full enclosure. This allows the implementation of typical car like safety features (seat belts, roll over structure, crush zones, air bags). The SafeRide&trade; tilting control system is a passive system that involves the driver&rsquo;s balancing sense in its feedback control system. The vehicle has typical scooter like steering characteristics, where the steering is initiated through countersteering. Another safety critical design feature is the crush zone between the two front wheels which is not possible with only one front wheel or with the powertrain positioned between the front wheels, as the powertrain can&rsquo;t absorb a lot of energy due to its structural stiffness and density. The passive tilting control system is quite simple and therefore makes the vehicle very affordable, an important factor for successful commercialisation.Another advantage of integrating the human balancing senses in the feedback control of the tilting system is that the system kicks in slightly after the human balancing reacts. In some instances that can generate the typical adrenalin thrill known from riding a bike. This fun factor is quite common with many trend sports like mountain biking, surfing, roller-skating, snowboarding, or skateboarding. Some of these sports have seen very rapid growth only a short time after they have been invented. Utilising the human balancing system during driving also makes the vehicle safer as the adrenalin is produced after reaching a semi-stable driving condition that is controlled by the vehicles tilting control system, but before the vehicle reaches an unstable driving condition that can not be controlled by the vehicle but only (eventually) by the driver &ndash; if he has got the required driving skill and if he is alert enough.Efficiency superior to most cars and scooters is achieved by the aerodynamics of a fully enclosed body structure in combination with the small frontal area of a typical scooter and the droplet shape enabled by the relatively wide front with 2 wheels and the very narrow tail with only one rear wheel. The passive tilting system also contributes to the extreme efficiency as the system only draws some small electrical power for the electronic control unit. Another feature is a low cost exhaust energy recovery system which is discussed in another paper.<br /

A new method to warm up lubricating oil to improve the fuel efficiency during cold start

Cold start driving cycles exhibit an increase in friction losses due to the low temperatures of metal and media compared to normal operating engine conditions. These friction losses are responsible for up to 10% penalty in fuel economy over the official drive cycles like the New European Drive Cycle (NEDC), where the temperature of the oil even at the end of the 1180 s of the drive cycle is below the fully warmed up values of between 100&deg;C and 120&deg;C. At engine oil temperatures below 100&deg;C the water from the blow by condensates and dilutes the engine oil in the oil pan which negatively affects engine wear. Therefore engine oil temperatures above 100&deg;C are desirable to minimize engine wear through blow by condensate. The paper presents a new technique to warm up the engine oil that significantly reduces the friction losses and therefore also reduces the fuel economy penalty during a 22&deg;C cold start NEDC. Chassis dynamometer experiments demonstrated fuel economy improvements of over 7% as well as significant emission reductions by rapidly increasing the oil temperature. Oil temperatures were increased by up to 60&deg;C during certain parts of the NEDC. It is shown how a very simple sensitivity analysis can be used to assess the relative size or efficiency of different heat transfer passes and the resulting fuel economy improvement potential of different heat recovery systems system. Due to its simplicity the method is very fast to use and therefore also very cost effective. The method demonstrated a very good correlation for the fuel consumption within &plusmn;1% compared to measurements on a vehicle chassis roll

Parameter estimation on compact binary coalescences with abruptly terminating gravitational waveforms

Gravitational-wave astronomy seeks to extract information about astrophysical systems from the gravitational-wave signals they emit. For coalescing compact-binary sources this requires accurate model templates for the inspiral and, potentially, the subsequent merger and ringdown. Models with frequency-domain waveforms that terminate abruptly in the sensitive band of the detector are often used for parameter-estimation studies. We show that the abrupt waveform termination contains significant information that affects parameter-estimation accuracy. If the sharp cutoff is not physically motivated, this extra information can lead to misleadingly good accuracy claims. We also show that using waveforms with a cutoff as templates to recover complete signals can lead to biases in parameter estimates. We evaluate when the information content in the cutoff is likely to be important in both cases. We also point out that the standard Fisher matrix formalism, frequently employed for approximately predicting parameter-estimation accuracy, cannot properly incorporate an abrupt cutoff that is present in both signals and templates; this observation explains some previously unexpected results found in the literature. These effects emphasize the importance of using complete waveforms with accurate merger and ringdown phases for parameter estimation.Comment: Very minor changes to match published versio

Realization of Hilbert Space Fragmentation and Fracton Dynamics in 2D

We propose the strongly tilted Bose-Hubbard model as a natural platform to explore Hilbert-space fragmentation (HSF) and fracton dynamics in two-dimensions, in a setup and regime readily accessible in optical lattice experiments. Using a perturbative ansatz, we find HSF when the model is tuned to the resonant limit of on-site interaction and tilted potential. First, we investigate the quench dynamics of this system and observe numerically that the relaxation dynamics strongly depends on the chosen initial state -- one of the key signature of HSF. Second, we identify fractonic excitations with restricted mobility leading to anomalous transport properties. Specifically, we find excitations that show one dimensional diffusion (z = 1/2) as well as excitations that show subdiffusive behaviour in two dimensions (z = 3/4). Using a cellular automaton, we analyze their dynamics and compare to an effective hydrodynamic description.Comment: 4+4 pages, 7 figure

In The Afterglow

https://digitalcommons.library.umaine.edu/mmb-vp/5031/thumbnail.jp

Automatisierte Baumaschinen und Robotik

Die Bauwirtschaft sieht sich gegenwärtig und wohl auch in naher Zukunft mit einer großen Nachfrage nach Baumaßnahmen zur Schaffung von Wohnungen und Infrastruktur konfrontiert. Diesem Bedarf stehen ein nicht zu übersehender Mangel an Fachkräften und zunehmende Regularien und Qualitätserwartungen während des gesamten Bauprozesses gegenüber. Verglichen mit anderen Wirtschaftsbereichen hat die Baubranche zudem erheblichen Nachholbedarf im Hinblick auf ihre Produktivitätsentwicklung. So zeigen dahingehend nahezu alle Industrie- und Dienstleistungsbereiche einen mehr oder weniger kontinuierlich ansteigenden Trend, wohingegen die Produktivität in der Bauwirtschaft seit Jahrzehnten stagniert. Um diesen Anforderungen erfolgreich begegnen zu können, bieten die aktuell in allen Bereichen diskutierten Digitalisierungsansätze auch bei Baumaßnahmen und Baumaschinen nicht unerhebliches Potenzial. Dennoch gibt es bisher nur eine vergleichsweise geringe Durchdringung des Marktes mit industriell tauglichen Digitalisierungslösungen in der Bauwirtschaft. Vor diesem Hintergrund entstand das vorliegende Gutachten zum Thema „Automatisierte Baumaschinen und Robotik“, welches im Wesentlichen auf die Möglichkeiten und Grenzen der Automatisierung etablierter Baumaschinen durch die Integration verfügbarer Technologien zielt. Darüber hinaus werden neuartige und für den Einsatz in der Bauwirtschaft speziell konzipierte Technologien und Maschinen betrachtet. Dabei gewährt das Gutachten einen freien Blick auf den aktuellen Stand angewandter Technologien, Prozesse und Maschinen, zeigt weiterführend erkennbare Entwicklungstrends auf und klassifiziert Potenziale zur Effizienz-, Qualitäts- und Produktivitätssteigerung

Assimilation of All-Weather GMI and ATMS Observations into HWRF

We propose a novel Bayesian Monte Carlo Integration (BMCI) technique to retrieve the profiles of temperature, water vapor, and cloud liquid/ice water content from microwave cloudy measurements in the presence of TCs. These retrievals then can either be directly used by meteorologists to analyze the structure of TCs or be assimilated to provide accurate initial conditions for the NWP models. The technique is applied to the data from the Advanced Technology Microwave Sounder (ATMS) onboard Suomi National Polar-orbiting Partnership (NPP) and Global Precipitation Measurement (GPM) Microwave Imager (GMI)