Konrad Nering

This paper is devoted to numerical studies of composite structures with delaminations made with the use of CDT. Analysis of temperature distribution provides the opportunity to determine the geometry of subsurface defects. Results confirm the validity of the FE model in comparison to previous experimental investigations.

In this paper the analysis of performance characteristics of a cross flow fan working as an element of the unit incorporating heat exchanger as well as performance characteristics of the unit are presented. These experimental results were basic for consideration of pressure losses arising as an effect of direct connection of a cross flow fan and a heat exchanger located in the charging zone of the fan as a resistance. Analysis of an influence of rotational speed variation as well as a medium temperature on aerodynamic characteristics of heat exchanger let to propose a method for the local pressure loss estimation.

The paper presents a method for monitoring the flow conditions in pipelines in the case of transport of crystallising water slurries forming scale. The method’s core is the ability to calculate the equivalent pipeline diameter under varying flow conditions in industrial practice. The method was successfully tested in the laboratory and employed in an industrial plant.

In this paper some selected problems dealing with an influence of different throttling conditions on the flow structure inside a cross flow fan working in a unit incorporating a heat exchanger as well as on aerodynamic performances of a cross flow fan and unit have been studied. Different experimental and numerical methods have been used to verify and confirm selected flow phenomena. The local pressure loss as an effect of a heat exchanger resistance has been estimated taking into consideration some experimental results confirmed by the Finite Volume Method computation.

Niniejszy artykuł przedstawia badania redukcji poziomu dźwięku poprzez zastosowanie materiałów tekstylnych wokół rurociągów. Źródłem hałasu jest szum kawitacyjny. W celu wyznaczenia spadku poziomu hałasu dla materiału izolacyjnego ułożonego wokół rury – geometria cylindryczna – zmierzono spektrum widma akustycznego w zakresie słyszalnym przez człowieka. Pomiary przeprowadzono dla materiałów tekstylnych ułożonych z różną ilością warstw wokół źródła szumów. Zaobserwowano spadek poziomu szumów charakterystyczny dla prawa masy. W ramach opracowania wyników wyznaczono wzór empiryczny opisujący względną redukcję poziomu szumów dla badanych materiałów. 

This article presents an examination of the acoustic noise level reduction in piping applications. Hydraulic cavitation is the source of the noise. In order to determine the noise level drop for the insulating material arranged around the pipe – cylindrical geometry – the acoustic spectrum was measured in the range of audible frequencies. Measurements were made for textile materials stacked with varying amounts of layers around the source of noise. There was a decrease in the noise level characteristics for mass law. An empirical formula describing the relative noise reduction for the materials under study was proposed.