Heat Sink Shape and Topology Optimization with Pareto-Vector Length Optimization for Air Cooling

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Intelligens napelemes rendszer vizsgálata = Analysis of smart photovolatic systems

Nowadays more attention should be paid to the electric power generation wi th renewables. The photovoltaic systems have several benefits. But this systems power output could drastically drop by numerous external phenome. To avoid these, we introduce the so called “TIGO” power opti mizing system features and the monitoring of the deployed system on an existing building. We examine the produced energy for a given time period.Napjainkban egyre nagyobb figyelmet kell fordítanunk a megújuló energiaforrásokkal történő villamos energiatermelésre. A napelemes rendszer számos előnnyel rendelkezik. Viszont a rendszerek teljesítménye külső hatásra drasztikusan lecsökkenhet. Ezek elkerülése végett egy konkrét épület segítségével bemutatjuk a TIGO teljesítmény optimalizáló rendszer elemei t, előnyeit és moni toringját. Elemezzük az adott időszakra vonatkoztatott termelési adatokat

Simulation of Temperature Distribution on the Face Skin in Case of Advanced Personalized Ventilation System

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Numerical Model Analysis of Natural Gas Combustion Burners

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Szélcsatornaépítés a gyakorlatban = Wind tunnel making in practise

In this paper, we examined the low speed wind-tunnels. Our goal is to construct an open flow system windtunnel that can be utilized in our measurements. To make such a wind-tunnel we needed to build a prototype and calibrated with the help of measurements. Than we determined the flow at the area of measurement. Finally results of the measurements satisfied our expectations. Although there is still much more in development that we would like to do based on the newly gained experience.Cikkünkben a kis sebességű szélcsatornával foglalkoztunk. Célunk az volt, hogy létrehozzunk egy olyan nyitott rendszerű szívott légcsatornát, melynek segítségével a későbbiekben méréseket végezhessünk. Ehhez szükséges volt a szélcsatorna prototípusának megalkotása és kalibrációs mérések elvégzése, hogy a mérőtérben uralkodó áramlásviszonyokat feltérképezzük. A szélcsatornánkban teljesültek várakozásaink, de számos ponton van tér még a fejlesztésre, amit a levont tapasztalatok alapján kívánunk megtenni

Calculations of Performance Losses for Automobile Vehicles

Vehicle-energetic-models are used to analyze the performances and when a comprehensive structure is established even optimization could be done. For these kinds of models, the losses of the vehicles have to be known. These losses could significantly effect of the vehicle fuel consumption. From these losses the rolling resistance, drive elements and aerodynamic drag are discussed. This paper reviews some of the literatures that describes the calculation methods and gives us some idea about the degree of their value. Our further goals are to have an UpToDate loss coefficient dataset and calculation methods for further vehicle-energetic modelling

Analysis of the change of the specific heat loss coefficient of buildings resulted by the variation of the geometry and the moisture load

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Az alföldi szélenergia-potenciál vizsgálata

Vizsgálataink célja, hogy áttekintsük a szélenergia hasznosítás lehetőségét, olyan kevésbé előnyös szélrajzzal rendelkező területeken, mint az alföldi városok. Szemléltető példaként Hajdúszoboszló városát választottuk. A vizsgálataink során a hajdúszoboszlói reptér széladatait használtuk fel. A széladatok elemzése során az adatsorunkat Weibull eloszlással becsültük, paramétereit iterálással határoztuk meg. A széleloszlás vizsgálata után a potenciális szélenergiát vizsgáltuk meg. A szélviszonyok és a városias környezet állította feltételeket figyelembe véve arra a következtetésre jutottunk, hogy egyik turbina típus sem képes tökéletesen kielégíteni azokat. A feltételek figyelembe vételével egyedi szélturbina fejlesztése szükséges. Melynek fejlesztése jelenleg is zajlik

Heat Sink Shape and Topology Optimization with Pareto-Vector Length Optimization for Air Cooling

Localized air cooling can be used for various purposes, e.g.: electronic equipment cooling, and air conditioning. The paper emphasizes that the connection between the air-flow and cooling has to fulfill a contradictory requirement (low pressure loss and effective cooling). The cooling and the pressure loss are dependent on the moisture content of the air flow. In the study, heat sink geometries were examined at various fresh air relative humidity, temperature and flowrates with commercially available simulation software (Ansys Fluent). The most favorable option was chosen by Pareto-vector length optimization. For optimization, head loss coefficient and temperature coefficient were used. Firstly, 108 cases were made to evaluate the sensitivity of the optimization parameters. Secondly, on 40 finned heat sinks with different fin width and quantity optimization were made. Thirdly, a prototype was made from the favorite solution where the performance was evaluated. For the measurement two type: TEC1-12706 thermoelectric cooling devices (TEC) were used for cooling. The difference between the measured and the modelled cooled air temperatures was 3%

Numerical Assessment of Side-Wind Effects on a Bus in Urban Conditions

The drag coefficient is usually considered to be a constant value, which allows us to calculate the aerodynamic losses. However, at lower speeds and wind, this value could be distorted. This also applies to buses in urban environments where due to traffic, the speed is relatively low. Since the schedule of the buses is fixed, based on the driving cycle, they travel at a nominal cruising speed. This makes it possible to examine the drag losses in a quasi-steady condition. To find the magnitude of this distortion in losses, a large-eddy simulation method was used with the help of commercially available software. Symmetrical and asymmetrical flows were induced into the digital wind tunnel to assess the distribution of the forces in the cruising direction and examine the flow patterns. It was discovered that the drag forces behave differently due to the low speeds, and calculations should be performed differently compared to high-speed drag evaluations