Wyniki wyszukiwania - BazTech

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Possibile Applications of Magnetic Microwires in Aviation

Draganová K., Blažek J., Praslička D., Kmec F.

Fatigue of Aircraft Structures

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2013

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Iss. 5

12--17

EN

Magnetic microwires have been rediscovered due to a number of the unusual magnetic properties and their potential applications. The paper concerns glass-coated magnetic microwires composed of a ferromagnetic metallic core with a diameter of 0.6 – 30 μm and of a glass coat with a thickness of 2 – 20 μm. The fabrication process and magnetic properties of these microwires are described. Due to their unique properties microwires can be used as a sensing element of sensors. Microwire-based sensors can be used in a wide range of aviation applications as magnetic field sensors, tensile stress sensors or temperature sensors. The main advantages of microwire-based sensors are associated with their small dimensions and weight, which play a very important role in aviation.

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Advanced Magnetic Materials for Aeronautics

Šmelko M., Praslička D., Blažek J.

Fatigue of Aircraft Structures

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2013

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Iss. 5

60--65

EN

In the field of magnetic sensors, magnetic microwires with positive magnetostriction are the materials of the future. Their mechanical and magnetic properties render them ideal materials for applications in aeronautics. A single microwire with a 40 μm diameter and a length of 10 mm is capable of capturing information about tensile stresses, magnetic fields, temperature and distance. This information is carried by a parameter called the Switching Field, HSW, which is specific for different types of microwire. Numerous physical qualities affect the HSW and through sensing of HSW, these qualities may be quantified. (A number of physical qualities affecting HSW can be sensed and quantified by means of a contactless induction method.) What distinguishes the system developed by the present authors from other measuring systems based on magnetic microwires is the positioning of a microwire outside the coil system. Thanks to this improvement it is possible to use microwires embedded directly in the construction material. Small dimensions microwires do not damage the structure of the construction material. The absence of a galvanic connection makes this technology even more interesting compared with traditional forge gauges. Offering the possibility of the simultaneous measuring of four parameters, this technology can be used in a wide range of aviation applications. Measurements of an external magnetic field can be used for the navigation and stabilization of an aerial vehicle. Tensile stress and distance measuring can be helpful to understand some processes occurring under the surface of the construction material and also to perform fatigue monitoring or structure load monitoring. Another big advantage of magnetic microwires is the low price. Just 1 gram of base material is sufficient to prepare about 40 km of microwire. All these features combine to offer us a material ideal for Smart Sensors, possibly available for use in the near future.

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Simulation model of combustion engine with direct injection of hydrogen

Blažek J., Brabec P.

Journal of KONES

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2009

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Vol. 16, No. 3

15-21

EN

Fuel mixture formation inside a cylinder has become used more frequently in spark ignition engines in recent years. gas internal combustion engines can also benefit from this concept as direct injection into an engine 's cylinder during the compression stroke not only increases its volumetric efficiency but also eliminates adverse anomalies in the combustion process. This paper focuses on the development of a simulation model for a spark ignition engine with direct hydrogen injection into a cylinder. The Wave software was used for the simulation. A part of the paper depicts the model's verification. The study utilized a three-cylinder internal combustion engine with the total cylinder volume of 1.2 dm3. The concept of the engine is based on new, high-pressure injectors with 10 MPa inlet pressure (gas-hydrogen injection directly into the engine cylinder). Utilization of internal fuel mixture formation can be beneficial due to its enabling the control of the combustion process and gaseous emission generation. From the viewpoint of the engine's design, however, internal fuel mixture utilisation is more complicated as injectors have to be built into the cylinder head. The actual engine construction is housed in laboratories of the Technical University of Liberec, Department of Vehicles and Engines.

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Automotive SI engine with injection of the liquid LPG into the inlet manifold

Mareš J., Beroun S. S., Blažek J., Holubec R.

Journal of KONES

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2007

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Vol. 14, No. 3

385-394

EN

Non supercharged SI engine on LPG with mixture forming by evaporated LPG has lower power by about 8% compared to original petrol engine. This disadvantage can be eliminated by mixture forming by injection of liquid LPG. Report shows the results of the laboratory experimental research on an engine with injection of liquid LPG with the detailed analyses of the energy, power and emission engine parameters in 2 variations of the engine set-up. The thermodynamic analysis of the indicator diagram has shown that the characteristic parameters of the cycle (incl. Parameters of the combustion course) stand practically identical for operation on petrol and on LPG. The measurements on the engine were also oriented on study of conditions in the inlet manifold after injection of the liquid LPG (injection visualization with fuel vaporization, temperature in the intake port) for an explanation of any abnormality on course of the unburned hydrocarbon concentration before catalyst. The experimental results show that automotive engine with injection of liquid LPG like high-quality variation of the car drive with favorable operating economy and positive ecological effects for environment.