BazTech - Yadda

1

Application of the ASTM D5470 standard test method for thermal conductivity measurements of high thermal conductive materials

Buliński Z., Pawlak S., Krysiński T., Adamczyk W., Białecki R.

Journal of Achievements in Materials and Manufacturing Engineering

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2019

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Vol. 95, nr 2

57--63

EN

Purpose: The purpose of the present study was to demonstrate the procedure for determining the thermal conductivity of a solid material with relatively high thermal conductivity, using an original self-designed apparatus. Design/methodology/approach: The thermal conductivity measurements have been performed according to the ASTM D5470 standard. The thermal conductivity was calculated from the recorded temperature values in steady-state heat transfer conditions and determined heat flux. Findings: It has been found from the obtained experimental results that the applied standard test method, which was initially introduced for thermal conductivity measurements of thermal interface materials (TIMs), is also suitable for materials with high thermal conductivity, giving reliable results. Research limitations/implications: The ASTM D5470 standard test method for measurement of thermal conductivity usually gives poor results for high conductive materials having thermal conductivity above 100 W/mK, due to problems with measuring heat flux and temperature drop across the investigated sample with reasonably high accuracy. Practical implications: The results obtained for the tested material show that the presented standard test method can also be used for materials with high thermal conductivity, which is of importance either for the industrial or laboratory applications. Originality/value: The thermal conductivity measurements have been carried out using an original self-designed apparatus, which was developed for testing broad range of engineering materials with high accuracy.

2

Numerical modeling and preliminary validation of drag-based vertical axis wind turbine

Krysiński T., Buliński Z., Nowak A. J.

Archives of Thermodynamics

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2015

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Vol. 36, no. 1

19--38

EN

The main purpose of this article is to verify and validate the mathematical description of the airflow around a wind turbine with vertical axis of rotation, which could be considered as representative for this type of devices. Mathematical modeling of the airflow around wind turbines in particular those with the vertical axis is a problematic matter due to the complex nature of this highly swirled flow. Moreover, it is turbulent flow accompanied by a rotation of the rotor and the dynamic boundary layer separation. In such conditions, the key aspects of the mathematical model are accurate turbulence description, definition of circular motion as well as accompanying effects like centrifugal force or the Coriolis force and parameters of spatial and temporal discretization. The paper presents the impact of the different simulation parameters on the obtained results of the wind turbine simulation. Analysed models have been validated against experimental data published in the literature.

3

Laboratoryjne badania ciśnienia rozprężania węgla w procesie koksowania

Krysiński T., Czerwiński M.

Elektronika : konstrukcje, technologie, zastosowania

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2013

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Vol. 54, nr 4

95-97

PL

Artykuł przedstawia koncepcję modelowego urządzenia do pomiaru ciśnienia rozprężania węgla w baterii koksowniczej występujące podczas procesu koksowania węgla. To groźne zjawisko, występujące prawie zawsze podczas koksowania węgla może doprowadzić do zniszczenia ścian baterii koksowniczej. Dotychczasowe próby laboratoryjnego pomiaru ciśnienia wykorzystywały badanie małych (do 100 g) próbek mieszanki węglowej ogrzewanych w piecach elektrycznych, lub koksowania dużych próbek (200...500 kg) w dużych murowanych piecach z kanałami w ścianach, ogrzewanymi gazowo. Efektywność obu metod jest niska, ponieważ wyniki uzyskiwane z próbek małych nie są adekwatne do zjawiska na dużej baterii, zaś urządzenia duże są zbyt pracochłonne i energochłonne a czas jednego testu wynosi kilka dni. Model opracowany w ITR ma ogrzewaną elektrycznie, prostopadłościenną komorę o pojemności 15 dm³ wyposażoną w dwie ruchome boczne ściany - do kompensacji powstającego ciśnienia i dwie otwierane ściany - do bocznego załadunku mieszanki węglowej i rozładunku gorącego koksu z komory po procesie.

EN

This article presents a conception of laboratory model device for coke pressure measurement, what is generated in coke battery cell during cocking process. This danger occurrence, what have take place in almost every cocking process may destroy battery cell walls. Until now, laboratory devices for evaluating the pressure used small coal samples (up to 100 g) heated with electric ovens, or big samples heated inside furnaces made of bricks, with wall channels, heated by gas. Effectiveness of both methods is low, for not addictive results obtained from small samples and too big job and energy consumption with big samples, in additionally time for executing one big sample test is days. The model, designed in ITR has electric heated rectangle chamber with capacity of 15 l, equipped with two side walls fixed movable - for compensation of coal pressure generated and two other open able walls - for side chamber loading with coal sample and hot coke discharging after process.

4

Active Methods for Low-Vibration Helicopters

Malburet F., Krysiński T.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

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2005

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nr 128, vol. 2

357-372

EN

The reduction of helicopter vibrations has traditionally been a difficult task to perform. Current anti-vibration devices are passive or semi-active and have now reached their limits in terms of performance and vibration reduction. Moreover they are less adapted to variable NR, which is now present in all new developments because of its aerodynamics and acoustic achievement. It is therefore ineluctable to develop an active anti-vibration device. This paper is devoted to a new generation of active anti-vibration systems developed for the helicopter. It gives an overview of the development methodology from the initial theoretical calculations up to flight test validation.