The paper presents a numerical study on the heat transfer and pressure drop, related to flow in pipes with helical micro-fins. For all tested geometries, one applied a constant wall heat flux and fully developed 3D turbulent flow conditions. The influence of the angle of micro fins (referred to the tube axis) on thermal-flow characteristics were tested. The value of this angle was varied – with a step of 10 degrees – from 0 to 90 degrees (representing grooves parallel and perpendicular to the axis, respectively). Before numerical investigation, the pipe with helical angle of 30 degree was tested on an experimental stand. The results obtained from experiment and numerical simulations were compared and presented on the charts. As an effect of the numerical simulations, the friction factor f and Nusselt number characteristics was determined for the range of Re=104/1.6x106. The analysis of the results showed high, irregular influence of the helical angle on thermal characteristics and pressure drops. Additionally, the ratios: f/fplain, Nu/Nuplainand efficiency indexes (Nu/Nuplain)/( f/fplain) as a function of the Reynolds number for every helical angle were shown on the charts.

The research material in this article is V. Nabokov’s short story A Nursery Tale (1926), which, by virtue of the literary genre signalled in the title, disposes us to consider the author’s communicative intention. The methodological inspiration for the research is M. Bakhtin’s genological reflection and his concept of the genre as “a representative of creative memory in the process of literature development”; W. Propp’s study and J. Derrida’s idea about fairy tales has also proved helpful. Analysis and interpretation of the short story A Fairy Tale has allowed one to distinguish particular elements and devices aimed at the short story genre transformation with special regard to the titular (fairy-tale) form of expression. The special status of the work’s protagonist is demonstrated, his creative activity understood as a kind of game, whose creator and actor is the protagonist himself, while the realisation of his erotic desire is treated as a way of regarding Femininity and of opening to “the other”, precisely connected in Nabokov’s short story with the female figure. On the parabolic/fabulous level the hero’s dream (collecting “a harem of women”) is interpreted as a literary device – an expression of romantic irony revealing the opposing forces governing human existence, a conflict between everyday reality and the world of creative fantasy/imagination. In consequence, Nabokov’s A Nursery Tale is read as an example of a narrative parabolic fairy tale.