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Thermal performance analysis of manned airships in a thermally variable environment

Shi Hong, Liu Meinan, Chen Jiamin, Zou Yitao

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 5

art. no. e143105

EN

The safety and reliability of the manned airship depend to a considerable extent on its thermal performance. In this paper, heat balance equations are developed and solved in the C++ programming language. The temperature variation of the enclosure, gasbag, and nacelles of the manned airship is investigated. In addition, the effects of season, latitude, and orientation on the thermal performance of the manned airship and the airship nacelle are investigated. The results show that: (1) The average temperature difference of the nacelle surface at the same time is 25 K, while the maximum temperature difference in the nacelle is 29 K during the day, (2) the temperature distribution in the nacelle is similar in spring and autumn, with maximum temperature between 306 K and 309 K. The maximum temperature in the nacelle is between 300 K and 303 K in winter while the maximum temperature in the nacelles is between 309 K and 315 K in summer, (3) as the flight position of the manned airship changes from 20°N to 60°N, the average nacelle temperature varies slightly by about 1 K. However, as the latitude increases, the high- temperature region shifts from the bottom of the nacelle to the side of the nacelle, and (4) the temperature distribution of the upper envelope of the airship varies considerably with orientation. However, the average temperature of the nacelle is less impacted by orientation. These results are useful for understanding the thermal performance of manned airships.

2

Solutions for increasing the capacities of cable cars

Težak Sergej, Lep Marjan

Journal of Sustainable Development of Transport and Logistics

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2019

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Vol. 4, No. 1

31--37

EN

Cableways have some potential to be used in urban public transportation, particularly uni-directional aerial cable cars with circulating cabins, called gondolas. They have several advantages, but two major problems must be solved: the capacity and the operating speed are not competitive when compared to other means of urban mass transport because of boarding procedures and slowing down and accelerating on intermediate stations. In this paper constructional solutions are presented. Boarding takes place on at least two platforms; these could be on the same level or on separate levels. At intermediate stations certain cabins are diverted to the extra platform while the majority of cabins travel with unreduced speed. Following this constructional approach, the nominal capacity of gondolas could be doubled while increasing the operational travel speed on lines with lot of intermediate stops.

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Wpływ obecności gondoli na kształt łopat wirnika turbiny wiatrowej o poziomej osi obrotu

Woźniak A.

Materiały Budowlane

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2014

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nr 5

38--40

PL

Dobrze znane metody konstrukcji łopatek turbin wiatrowych o poziomej osi obrotu oparte są na napływie jednorodnym [1], natomiast prawdziwe turbiny wiatrowe pracują w niejednorodnym strumieniu. Przyczyną tej niejednorodności może być obecność gondoli wiatraka. Celem artykułu jest przedstawienie wpływu obecności gondoli na kształt łopatek wirnika turbiny wiatrowej, tj. kształt cięciwy i kąta skręcenia.Opisanametoda łączy twierdzenie Betza o minimalnej mocy indukowanej śmigła z modyfikowaną teorią opływu ciała smukłego oraz zasadą zachowania pędu i momentu pędu w przypadku elementu łopaty wirnika.

EN

Well established methods of wind turbine blades aerodynamic design are founded on assumption of uniform inflow. Real wind turbine works in non-uniform stream affected by vertical velocity gradient, nacelle. It seems that the effect for small turbine will be strong. The purpose of the present paper is investigation of nacelle on shape of the blade i.e. radial chord and twist distribution in so-called reverse (design) problem for HAWT. In the paper a sample calculations of the rotor geometry for given conditions has been presented. It was shown that the presence of nacelle has an appreciable influence on twist and chord distribution in the inner portion of the rotor disk.

4

Komunikacją miejską po wodzie

Nowakowski P. T.

Komunikacja Publiczna

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2014

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nr 1

54--61

PL

Wenecja wzniesiona jest na archipelagu 126 bagnistych wysp, poprzecinanych przez 182 kanały płytkiej laguny, a połączonych ze sobą dzięki 433 mostom. Kanały pełnią w starej części miasta funkcję swoistych dróg. Tutaj, tak jak przed wiekami, poruszać się można tylko transportem wodnym albo na piechotę.