2,893 research outputs found
Revised KAD Tool To Optimize F1 Cars Through A Combined-Elitarian Genetic-Fuzzy Algorithm
No full textTheKAD(Knowledge Aided Design) tool is developed to predict the performance of an F1
car in different driving conditions and with different configurations. The regulations to put in trimming
a car, also in the exasperated technology of the competitions, still demand a remarkable dose of luck
and an elevated number of tests. It is then important to know a set of regulations close to the optimal
trim before testing the car on the track. The difficult phase of this process is to evaluate the lap time. As
a matter of fact driving style, track conditions and car behavior should be simulated. The optimisation
of the fuzzy controller that simulates the pilot for an F1 racing car is difficult due to handling problems
and velocity of response. For this purpose a specific Genetic Algorithm (GA) was conceived and tuned
to work with a lumped mass model of an F1 racing car for the optimization of the fuzzy controller that
simulates the pilot. A new mutation and a new crossover operator were defined to complement the
standard crossover and mutation operators of the basic Holland’s GA. This was necessary in order
to increase the overall performance of the fuzzy pilot. This approach was tested on an F1 car due to
the huge amount of data availabl
Rozpor ako východisko, láska ako smer u Simone Weilovej (Contradiction as base, Love as direction in writings of Simone Weil)
No full textArticle is explaining contradiction and love, Simone Weil‘s essential terms of hermeneutics of human Being. It introduces close relation of these terms with her understanding of God as well as with her overall concept of religion. Author also mentions Simone Weil‘s inspirations with philosophical and spiritual concepts of the East
FUZZY LOGIC CONTROLLING MOTORBIKES ANTISKID
No full textActive antiskid systems for high performance motorbikes are difficult to implement due to the necessity to combine performance, equilibrium, handling and safety. In order to design and optimize a fuzzy controlled antiskid system for motorbikes, a fuzzy model of the pilot was applied to a lumped-mass model of the motorcycle (two different models have been considered). The fuzzy model acts on the steering angle to control trajectory, yaw angle, yaw velocity and roll angle
Feasible optimum design of a turbocompound diesel brayton cycle for diesel-turbo-fan aircraft propulsion
No full textThis paper is conceived to optimize the design of the thermodynamic cycle of a turbine (Brayton cycle) that uses a modern common rail diesel engine as an "active" combustion chamber. In this case the "active" combustion chamber produces the mechanical energy that drives the fan. The incoming air is compressed by the compressor, then is cooled (aftercooler) and inputted in the diesel engine. A high pressure common rail system optimizes the combustion in the diesel combustion chamber and the expansion begins inside the diesel engine. At the exhaust of the combustion chamber a turbine completes the expansion of the hot gases. A nozzle accelerates the exhaust from the turbine to increase the overall thrust. The mechanical energy from the diesel and from the turbine engizes the compressor and the fan. The system can be seen as a turbocharged diesel engine with the turbocharger that outputs energy to the turbofan, increasing the output power and or the efficiency. A diesel-turbine compound can be realized in this way. The coupling of the two system may be obtained in several different ways. The simplest is to put on the same shaft the compressor, the diesel crankshaft and the turbine. In front of the compressor a speed reducer drives the fan. A second example is to connect the turbine and the diesel on to electric generators. Electric engines are connected to the compressor and to the fan. The traditional turbo-diesel has the compressor coupled to the turbine, and the diesel engine that moves the fan. In this latter case, however, the turbine does not energize the fan. Many other hybrid and non hybrid solution are possible. The problem is to optimize temperatures, pressures and rpm to the different machines that form the compound. The availability of many experimental data for diesel and turbines makes it possible to obtain a design of a "true" feasible optimum Diesel-Brayton cycle. The high efficiency justifies the huge manufacturing and development costs of these turbocompound engines
“I beg you to tell me what has become of Djamila”: The Political Mobilization of Simone de Beauvoir’s Readers During the Boupacha Affair
No full textBy Sophia Millman This is a condensed version of a Masters thesis dedicated to the political mobilization of Simone de Beauvoir’s readers. The citations from the letters were translated from French by the author. *** On June 2, 1960, the French government ordered all copies of the daily Algiers edition of Le Monde seized and destroyed to suppress the publication of Simone de Beauvoir’s article “Pour Djamila Boupacha.” Beauvoir, a self-professed “woman of letters”, not “of action[1]”, and one ..
PISTON ENGINE COOLING: AN EVERGREEN PROBLEM
No full textImmediately before Wold War II (WWII), piston engine cooling has become a resource instead of a problem. The Meredith paper defined a static engine that converted the heat dissipated by the engine into thrust.
Some solutions (see the De Havilland Mosquito, Messerschmidt BF 109F, Supermarine Spitfire...) used hot air also to improve the efficiency of flaps.
In any case the Meredith effect proved to be effective even at the relatively low speed of F1 racing cars. The main problem proved to be a design.
In recent times turbodiesel piston common rail engines are coming back into the aircraft field. However the experience coming from the racing car field cannot be directly applied to the flying machines for many different reasons.
First of all racing rules usually ban moving flaps and variable geometry intake and exhausts, that are commonplace in aircraft (see for example supersonic air intakes). Moreover racing cars are relatively “dirty” reversed wing air machines, very different from the slender and elegant aircrafts.
Then the cooling system arrangement should be adapted to the necessity of the diesel engines and of the high altitudes.
This paper starts from the existing historical and new solutions and demonstrates that many improvements are still possible to improve the overall propulsion efficiency of new flying machines
METHODOLOGY TO EVALUATE AIRCRAFT PISTON ENGINE DURABILITY
No full textA main problem in aircraft engines is the evaluation of residual life to TBO. The algorithm described in this paper calculates with good reliability the residual life to TBO of a petrol piston engine. The method was tested on small last-generation naturally-aspirated-avio piston engine, and has demonstrated to be effective in several experimental tests. This method is implemented directly in the FADEC or ECU of the engine with very few lines of C-Code. The method can be used also in many industrial engines.
This innovative method assumes that only two main factors (load and wear) affect engine durability or Time Between Overhauls (TBO). These two factors are considered as separate and combined with the worst case criteria. The load is assumed to follow a logarithmic law and a formula similar to the Miner’s law for material fatigue is used, making possible to calculate the “load curve” with the knowledge of only two points. The “wear” curve is related to elapsed engine cycles, and is easy to implement since it is related to technological. The resulting algorithm is very simple and can be implemented in very few software lines with data collected from the already existing sensors
A comparative study of form and theology in the works of Flannery O'Connor and Simone Weil
No full textIn this comparative study of the form and theology of Flannery O'Connor and Simone Weil I interrogate how Weil's philosophical writings and her theology illuminate O'Connor's use of both narrative and non-fictional forms, and her Catholicism. The Introduction analyses how Weil's concept of superposed reading provides a new method of approaching both O'Connor, her writings, and O'Connor
studies, and focuses on how such apparently different women interconnect. Chapter One explores how both Weil and O'Connor attempt to write their theologies on the
souls of their readers yet are each subject to constraints imposed by form. Weil's concept of locating equilibrium between incommensurates is discussed, and her
distinctively philosophical approach to fictions and fictionality is used to investigate O'Connor's notion of prophetic fictions and the writer's role. Chapter Two assesses how both writers revivify Christian paradoxes. Weil's monstrous concept of affiiction, and O'Connor's use of the grotesque genre to jolt secular man into an
awareness of the sacred are scrutinised. Chapter Three studies how both writers consider an encounter between God and man is possible through the action of grace. My Conclusion interrogates how Weil's work can deepen our understanding of O'Connor's writings, and examines how successful O'Connor is at realising a truly
Christian literature. I conclude that despite being a writer of powerful fictions, O'Connor can not be totally successful in her mission as writer-prophet because
ultimately fiction escapes orthodoxy
Active antiskid system for handling improvement in motorbikes controlled by fuzzy logic
No full textActive antiskid systems for high performance motorbikes are difficult to implement due to the necessity to combine performance, equilibrium, handling and safety. In order to design and optimize a fuzzy controlled antiskid system for motorbikes a fuzzy model of the pilot was applied to a lumped-mass model of the motorcycle (two different models have been considered). The fuzzy pilot acts on the steering angle to control trajectory, yaw angle, yaw velocity and roll angle. Throttle position vs. time curve, gear and an adherence model between tire and road are given as input. The fuzzy pilot is implemented with Matlab/Simulink, and simply tries to keep equilibrium. Only measurable inputs were given as input variables of the antiskid fuzzy controller. The output is the percent reduction in throttle position. The motorcycle-fuzzy-pilot model proved to be quite accurate. Motorcycle maximum velocity resulted higher than the real one due to the simplifying hypothesis. In curves the fuzzy pilot is less efficient than the real pilot. In fact there was a low frequency oscillation around the optimum steering angle. This fuzzy controlled antiskid proved to work quite well since equilibrium is attained also in critical situations where the motorcycle-fuzzy-pilot model alone fails to keep equilibrium
Fuzzy control system for recovering direction after spinning
No full textThe progressive increase of tire-size has concurred to a sensitive improvement of the adherence with consequent increase of car safety. However, the wide tires have problems to expel the water in excess in heavy rain condition. For this reason the phenomenon of the aquaplaning is increasingly felt and is the cause of several automotive accidents. It is not a case that nearly all tire manufacturers supply "rain" tires and adherence in wet conditions is highly advertised. A typical accident happens when aquaplaning occurs in motorway at high speed. One or more tires lose adherence and the car begins to spin. If the pilot is not able to regain the initial direction, the car may hit the guardrail or another car. In this case the modern control systems like the ESP (Electronic Stability Program) and the ASR (Anti Skid Regelung) do not have time or are not able to manage a pre-spin or spin situation at elevated slip-angles. In this paper, a fuzzy control system able to deal with these conditions is introduced. The car has been simulated with a 9 DOF lumped-mass model that does not take into account suspensions and it considers a rigid car on smooth asphalt. The model of adhesion of the tire, instead, takes into account the effect of transverse forces on the longitudinal adherence. An expert pilot controls a high-speed spin with difficulty also. In this paper, a fuzzy control system that is able to control the brake torque on each single tire has been considered. The fuzzy control system works quite well and the car does not even enter in a true spin if enough adherence is present or if the slippery zone on asphalt is limited
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