15 research outputs found
LOOP NETWORK CALCULATION METHOD FOR AIR FLOW IN FLATS
Abstract: Open collector and single flue chimneys together with mechanical ventilation systems can pose considerable problems in one space in both technical and legal terms. We attempt to investigate this issue from a technical perspective and we examine specific cases. If collector and single flue chimneys are used together with mechanical ventilation, in certain cases the functioning of the chimney can be hindered and even serious accidents can occur. In this case study, we have elaborated a calculation method which can show the circumstances of the functioning. This calculation method will be presented through some examples. We believe that generalizations can be made based on these examples. This calculation method enables the creation of a software, which can be used by an expert to control the air flow. Thanks to this procedure, one can test the effect of the depression on the collector and single flue chimneys. Firstly, the method will be presented in the case of a flat with 14 pipes , 7 of which are basic pipes . Some calculation examples will be presented for the given flat. In the second part, the air supply of a whole level including three flats with 42 pipes , 22 of which are basic pipes and loops will be analyzed
Keywords: air flow in flats, calculation method, control, basic pipes and loop
Axial Gap Optimisation of Half Diameter Shifted Counter Rotating Dual Rotor Wind Turbine
General energy demand is continuously increasing due to the fact that wind turbines and other renewable energy sources have begun to appear in previously unexplored areas, such as on the roofs of buildings. In view of this demand, a new type of wind turbines described in this article could become one of the energy generating tools in a smart grid system. In this article, first conventional and unconventional wind turbines are reviewed with respect to efficiency. Then a Counter Rotating Dual Rotor Wind Turbine (CO-DRWT) construction is analysed with Computational Fluid Dynamics (CFD) codes considering a fixed radial and a variable axial distance. In the analysis, power coefficients were calculated for different configurations. It was found that in case of the dual rotor wind turbine, the optimal axial distance for half diameter radial shift was in the range of 0,2-0,25 diameter
COUNTER-ROTATING DUAL ROTOR WIND TURBINE LAYOUT OPTIMISATION
General energy demand is continuously increasing, thus the energy generating assets need to be optimised for higher efficiency. Wind turbines are no exception. Their maximum efficiency can be determined on a theoretical basis. The limit is approached by researches day by day, utilizing the latest developments in airfoil design, blade structure and new and improved ideas in conventional and unconventional wind turbine layouts. In this paper, we are reviewing the conventional and unconventional wind turbines and their place in smart cities. Then, an unconventional wind turbine design, the CO-DRWT (counter-rotating dual rotor wind turbine) is analysed with a CFD (computational fluid dynamics) code, varying the axial and radial distances between the two turbines. After the simulations, the power coefficients for the different turbine configurations is calculated. At the end of this paper, the simulations results are summarized and consequences are drawn for the CO-DRWT layouts
Roof Pitch Angle Examination for Wind Turbine Installation
Due to the current increase in energy demand, renewable energy sources and their utilization have become a priority. Thanks to the Smart Grid, which is currently under development, and with the help of the evolving technologies, we are trying to extract more and more energy from sources that we couldn’t exploit before or which weren’t economically viable. In this article, we examine the airflow field for a theoretical warehouse building, dependent on roof inclination angle. The purpose of the analysis was to select the optimal angle under which a roof mounted horizontal axis wind turbine (HAWT) could perform efficiently
A mezőgazdaságban alkalmazott axiális átömlésű ventilátorok nyomás- és sebességterének meghatározására alkalmas vizsgálati módszer továbbfejlesztése = Developing of the method for measurement of velocity- and pressure field of axial flow fan and its application in agriculture
A mezĹ‘gazdaságban alkalmazott egyszerű geometriájĂş Ă©s egyszerűen gyárthatĂł ventilátorok mĂ©rĂ©sĂ©nek Ă©s mĂ©retezĂ©sĂ©nek továbbfejlesztĂ©se terĂ©n lĂ©ptĂĽnk elĹ‘re. A mĂ©rĂ©s továbbfejlesztĂ©sĂ©ben a nyomás Ă©s sebessĂ©gtĂ©r mĂ©rĂ©sĂ©t pontosĂtottuk a mintavĂ©telezĂ©s Ă©s kiĂ©rtĂ©kelĂ©s továbbfejlesztĂ©sĂ©vel. Az egyszerű ventilátorok nĂ©hány tĂpusánál a perdĂĽletapadás kimĂ©rĂ©sĂ©vel mĂłdosĂtani tudtuk a mĂ©retezĂ©si eljárást a lapátszámra vonatkozĂł ideális nyomásnövekedĂ©s bevezetĂ©sĂ©vel. Ezen a terĂĽleten fĹ‘kĂ©nt Molnár IldikĂł tevĂ©kenykedett Ă©s majdnem elkĂ©szĂĽlt PhD Ă©rtekezĂ©sĂ©nek ez alkotja a fĹ‘ gerincĂ©t. A nagyobb lĂ©gteljesĂtmĂ©nyekre kĂ©pes ventilátorok csoportjának tervezĂ©sĂ©vel is foglalkoztunk, fĹ‘kĂ©nt a rácsszámĂtás irodalmi áttekintĂ©sĂ©vel Ă©s az anomáliák feltárásával Ă©s a helyes eredmĂ©nyek alkalmazásával. Ezt elsĹ‘sorban Fenyvesi Dániel dolgozta ki a szintĂ©n majdnem elkĂ©szĂĽlt PhD Ă©rtekezĂ©sĂ©ben. A fenti tĂ©mákban több TDK dolgozat is szĂĽletett. CFD számĂtására több irányban lĂ©ptĂĽnk. EgyĂĽttműködĂĽnk a koreai CEDIC co. Ltd-vel, az általuk kifejlesztett kĂłd eredmĂ©nyeivel összehasonlĂtjuk a mĂ©rĂ©si eredmĂ©nyeinket. | We have made some steps at the development of design and measurement of simple geometry and simply manufacturing axial flow fans used in agriculture. In the measuring the pressure and velocity field it was refined the data logger system and the evaluation. It was measured the vortex shrinkage at different simple axial flow fans and we have modified the ideal total pressure rise for infinite blade number to total pressure rise for finite blade number. IldikĂł Molnár investigated in this field and she will have finished the PhD thesis in the not far future. It was also investigated the higher efficiency group of axial flow fans, where the blade numbers are higher, like a grid. Fenyvesi Dániel, PhD student investigated the different types of design method. He had found some discrepancies in the literatures and he worked out a design method with the help of correct grid calculation method. He will have finished the PhD thesis in the not far future, too. Some TDK theses were worked in this OTKA program. We have made some steps forward with the CFD calculation, too. There is cooperation with the Korean CEDIC co. Ltd, and we can do a comparison between the measured result and their calculation results
SzĂ©lturbina telepĂtĂ©sĂ©hez tetĹ‘ dĹ‘lĂ©sszögĂ©nek vizsgálata
Napjainkban jelentkezĹ‘ egyre nagyobb energiaigĂ©ny miatt, elĹ‘tĂ©rbe kerĂĽlnek a megĂşjulĂł energiaforrások Ă©s kĂĽlönfĂ©le hasznosĂtási mĂłdjaik. A jelenleg kialakulĂłban lĂ©vĹ‘ okos hálĂłzat (Smart Grid), Ă©s a fejlĹ‘dĹ‘ technika segĂtsĂ©gĂ©vel egyre több olyan helyrĹ‘l is energiát prĂłbálunk kinyerni, melyekbĹ‘l eddig nem lehetet, vagy gazdaságilag nem volt cĂ©lszerű. CikkĂĽnkben egy kĂ©pzeletbeli raktárĂ©pĂĽlet környezetĂ©ben kialakulĂł áramlási kĂ©pet vizsgálunk meg, a tetĹ‘ dĹ‘lĂ©sszögĂ©nek fĂĽggvĂ©nyĂ©ben. A vizsgálat cĂ©ljául tűztĂĽk ki, hogy kiválasszunk egy dĹ‘lĂ©sszöget, mellyel a tetĹ‘re szerelt kisteljesĂtmĂ©nyű vĂzszintes tengelyű szĂ©lturbina optimálisan működhet
Comparing different CFD software with NACA 2412 airfoil
The engineering application's design process starts with a concept, based on our theoretical knowledge and continues with a numerical simulation. In our paper, we review the finite volume method (FVM) which is used generally for heat and fluid dynamic simulations.
We compare three different computational fluid dynamics (CFD) software (based in the fine volume method) for validating a NACA airfoil, which can be used for example in the aerospace industry for an airplane's wing profile, and it can be used for example in the renewable industry for a wind turbine's blade or a water turbine's impeller profile. At the end of this paper, the result of our simulations will be compared with a validation case and the difference between the CFD software and the measured data will be presented
Bűvös doktaéder, mint gépészeti szerkezet
A Rubik kocka sikerének köszönhetően sok ehhez hasonló térbeli logikai játék született a nyolcvanas évek elején. A szabályos és félszabályos testekből akkor igen sok szabadalom született. Az elsők között adtam be egy, az ikozaéder és a dodekaéder szabályos testekre épülő térbeli logikai játékokat.
Melyre hazai Ă©s több kĂĽlföldi országban is szabadalmat kaptam. Cikkemben ennek a szerkezetnek a felĂ©pĂtĂ©sĂ©t geometriai sajátosságait a játĂ©klehetĹ‘sĂ©geit szeretnĂ©m bemutatni
Lakások lĂ©gtĂ©rfogatának számĂtására kiterjesztett hurkolt hálĂłzatszámĂtási eljárás
NyĂltrendszerű gyűjtĹ‘- Ă©s egyedi kĂ©mĂ©nyek egyĂĽttes,
valamint gĂ©pi szellĹ‘ztetĂ©ssel közös lĂ©gtĂ©rben egyĂĽttműködve igen jelentĹ‘s problĂ©mákat vetnek fel mind műszaki mind jogi Ă©rtelemben. A kĂ©rdĂ©st műszaki szempontbĂłl igyekeztĂĽnk megvilágĂtani Ă©s vizsgálni konkrĂ©t esetekben. A gyűjtĹ‘- Ă©s egyedi kĂ©mĂ©nyekkel párhuzamosan működĹ‘ gĂ©pi szellĹ‘ztetĂ©s bizonyos esetekben a kĂ©mĂ©ny működĂ©sĂ©t megakadályozhatja
Ă©s akár sĂşlyos balesethez is vezethet. Jelen cikkben bemutatunk egy olyan számĂtási mĂłdszert, amellyel választ adhatunk konkrĂ©t esetekben a működĂ©s körĂĽlmĂ©nyeire