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A role of the heat and work uncompensated transformations in the balance of entropy and the turbomachinery eﬃcienc

Kowalczyk T., Ziółkowski P., Sławiński D., Cisak M., Badur J.

Transactions of the Institute of Fluid-Flow Machinery

2017

nr 135

11--27

The notion of heat uncompensated transformation has early been introduced by Clausius in 1854 and next, after ﬁfty years of forgetting, in 1904 Duhem has revalorized it and combined it with a new notion of work uncompensated transformation [3]. In this way the so-called ClausiusDuhem inequality has been established. In our paper we wish to present a novelized procedure of estimating the role of the uncompensated transformations of heat and work within the ﬂow of viscous and heat conducting working ﬂuid like water stream. The original procedure was introduced by Puzyrewski and it is essential in expressing of a local, in time and space, balance of entropy. Futhermore, this unique approach leads to redeﬁnition of the eﬃciency notion, as is usually applied to ﬂuid-ﬂow machineries, to a new one important in computational ﬂuid dynamics (CFD) three-dimensional modeling. As a result, it is shown that usage of the polytropic eﬃciency, instead of the isentropic eﬃciency, is more convenient and seems to be natural in CFD approach. Helpfully, we have also found a correlation between those two eﬃciency deﬁnitions with usage of proposed new dimensionless (criterion) number.