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THE INFLUENCE OF THERMAL RESISTANCE AND THERMAL MASS ON THE SEASONAL PERFORMANCE OF WALLING SYSTEMS IN AUSTRALIA

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Journal of Green Building 2015年第4期10卷 107-126页

作者： dariusz alterman Adrian W.Page Behdad Moghtaderi Congcong Zhang Trevor Moffiet The University of Newcastle Frontier Energy Technologies CentreAustralia

This paper describes an experimental investigation of the thermal performance of four Australian domestic walling systems(cavity brick,insulated cavity brick,insulated brick veneer and insulated reverse brick veneer)having various combinations of thermal insulation and of thermal mass location within the *** experimental analysis extends further the previous studies of the benefits of thermal mass on the overall thermal performance of building enclosures(Gregory et al.2008,Luo at al.2008,Alashaary et al.2009).The comparison is based on the time required to maintain thermal comfort for free-floating internal *** results clearly show that internal comfort levels are influenced by both the thermal resistance of the walls as well as the extent and location of the thermal mass,with neither parameter being the sole *** best thermal performance is therefore obtained by an appropriate combination of thermal mass and resistance,rather than focussing on the overall wall thermal resistance(R-value)alone.A new approach of density temperature plots for comparison of temperature variation is also used in the assessment of module thermal performance.

关键词： thermal mass thermal performance thermal resistance building enclosure temperature plots

New Leiderman–Khlystov Coefficients for Estimating Engine Full Load Characteristics and Performance

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Chinese Journal of Mechanical Engineering 2019年第6期32卷 192-205页

作者： dariusz Szpica Department of Mechanical Engineering Bialystok University of Technology

The paper presents a method of calculating the full load engine characteristics based on the Leiderman–Khlystov relation. Because the values of the coefficients of the discussed function available in literature were determined for obsolete engine designs, an attempt was made to update them. To this end, a chassis dynamometer was used where a database of results had been built for a variety of vehicles. Following the data collection, the coefficients for variety of fueling system(six groups: fuel injected gasoline and turbocharged gasoline, spark ignition LPG Ⅰ–Ⅱ and Ⅳ generation, naturally aspirated diesel and turbocharged diesel) were determined. The identification of the coefficients was carried out in Matlab-Simulink indicating the applicability of the said function for most of the engines, yet the recent popularity of turbocharged gasoline engines requires an additional analysis of the possibility of use of a different functional description. The full load engine characteristics is a basis for the vehicle performance characteristics and, further, for modeling of traffic in a variety of aspects of the vehicle operation.

关键词： Passenger car Combustion engines Full load engine characteristics Numerical identification

Coefficient of Engine Flexibility as a Basis for the Assessment of Vehicle Tractive Performance

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Chinese Journal of Mechanical Engineering 2019年第3期32卷 189-197页

作者： dariusz Szpica Faculty of Mechanical Engineering Bialystok University of Technology

The paper attempts to analyze full load characteristics of over 500 combustion engines. Using statistical tools, the author determined the value of the coe cient of flexibility. Engine flexibility is the capability of the engine to adapt to varying loads. Importantly, in the investigations, the author took into account the parameters calculated in the course of the investigations on a chassis dynamometer, i.e., actual, not taken from technical specifications of brand new vehicles. Di erent stages of operating wear allow a better characterization of the population. Subsequent utilization of the results in tractive calculations is more reliable. The engines were divided into in six groups, depending on the type of fuel system: fuel injected gasoline and turbocharged gasoline, spark ignition LPG, naturally aspirated diesel and turbocharged diesel. However, engines running on alternative fuels are characterized with a greater flexibility than the fuel injected base engines. Conformity of flexibility of fuel injected and LPG IV generation engines have been observed,which confirms the appropriateness of engine adaptation to alternative fueling. Gasoline engine supercharging allowed a reduction of the maximum engine speed of the maximum torque, which extends the range of analyzable speeds for flexibility and consequently, the flexibility as such.

关键词： Vehicle Tractive performance Flexibility coe cient Engine characteristics

The role of tree uprooting in the transporting of sediment and mixing of soil in the Tatra Mountains

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Journal of Mountain Science 2021年第1期18卷 38-50页

作者： dariusz STRZYŻOWSKI Institute of Geography and Spatial Management Jagiellonian UniversityGronostajowa 7Kraków 30-387Poland

Tree uprooting is an important process which leads to many geomorphic *** of the most important are the transport of sediment and mixing of *** aim of this article is to make a detailed examination of the magnitude of sediment transport caused by an extreme windthrow event in three severely affected ***,a comparison is made of the windthrow event with a mass movement event in the aspect of the magnitude of sediment transport and soil *** study was conducted in three second-to third-order catchments in the Tatra Mountains,where a strong foehn wind event caused extensive windthrow in 2013,and a high-magnitude rainfall event triggered mass movements in *** volume of sediment uplifted by the uprooting event was calculated based on the mapping of root plates using high-resolution(0.04 m)aerial images and measurements of root plate volumes conducted in the *** volume of sediment transported by shallow landslides was determined based on a Digital Elevation Model(DEM1-m resolution).Windthrows affected 34%,76%,and94%of the area of the investigated *** of the trees had fallen *** direction of treefall was influenced by the slope aspect and *** plates and pits covered 1.3%,4.8%,and 5.4%of the area of the *** flux generated by the uprooting event,calculated for the entire area of each investigated catchment ranged from 8.1×10^(–4) to 9.9×10^(–3) m^(3) m^(–1) event^(–1).This was notably lower than the sediment flux generated by the mass movement event(also calculated for the entire area of each catchment),which was 1.8-6.1×10^(–2)m^(3) m^(–1) event^(–1).By contrast,uprooting affected a much larger area than the mass movement event,which underlines its significant role in the mixing of soil.

关键词： Tree uprooting Windthrow event Slope processes Sediment flux Tatra Mountains

A Method for Optimum Heating and Cooling Boiler Components of a Complex Shape

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Journal of Thermal Science 2015年第4期24卷 364-369页

作者： Piotr Duda dariusz Rzasa Institute of Thermal Power Engineering Faculty of Mechanical EngineeringCracow University of Technology Al.Jana Pawla Ⅱ3731-864 CracowPoland BorgWamer Poland

A numerical method for determining a transient fluid temperature is *** method is formulated to minimize the total time of heating and cooling operation based on the assumption that maximum tensile and compressive total stresses in a solid can not exceed the allowable value during the entire *** method can be used for any construction element of a simple or complicated *** this method,material properties of solids can be assumed as constant or temperature *** method will be implemented for the heating operation of an outlet *** construction element is mounted in supercritical power *** outlet header is installed in the 460 MW power unit and it is designed for the working pressure of p_w=26.5 MPa and the steam working temperature of T_w=554℃.The results obtained from the proposed method will be compared with the calculations according to TRD 301-German boiler code.

关键词： heat transfer thermal stresses heating optimization steam boilers

A criterion for high-cycle fatigue life and fatigue limit prediction in biaxial loading conditions

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Acta Mechanica Sinica 2016年第4期32卷 696-709页

作者： Lukasz Pejkowski dariusz skibicki Faculty of Mechanical Engineering University of Science and Technology KaJiskiego 7 85-789 Bydgoszcz Poland

This paper presents a criterion for high-cycle fatigue life and fatigue strength estimation under periodic proportional and non-proportional cyclic loading. The criterion is based on the mean and maximum values of the second invariant of the stress deviator. Important elements of the criterion are： function of the non-proportionality of fatigue loading and the materials parameter that expresses the materials sensitivity to non-proportional loading. The methods for the materials parameters determination uses three S–N curves： tension–compression, torsion, and any non-proportional loading proposed. The criterion has been verified using experimental data, and the results are included in the paper. These results should be considered as promising. The paper also includes a proposal for multiaxial fatigue models classification due to the approach for the nonproportionality of loading.

关键词： criterion fatigue proportional invariant verified coordinates scatter cycle steels assumed

Prediction of Thermal Behavior of Pyrolyzed Wet Biomass by Means of Model with Inner Wood Structure

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Journal of Thermal Science 2015年第1期24卷 82-89页

作者： Sylwia Polesek-Karczewska dariusz Kardas Institute of Fluid Flow Machinery of Polish Academy of Sciences

A simplified one-dimensional transient model for biomass pyrolysis in a fixed bed cylindrical reactor has been formulated and experiments have been carded out to verify the calculation results regarding temperature distribu- tion. The mathematical model accounts for mass, momentum and heat transfer, including moisture evaporation and convection of pyrolysis gases. Numerical simulation has allowed to predict temperature and heat flux distri- bution, and the dynamics of feedstock devolatilization. Special attention has been devoted to the analysis of the effect of biomass moisture content on the pyrolysis process. The model of moisture vaporization in biomass bed was proposed, which included structure of surface of biomass particles. Assuming that vaporization occurs on the border of the dry and wet areas of the bed, the flux of water vaporization depends on the specific surface area of the particles and overall heat flux.

关键词： Pyrolysis Fixed Bed Evaporation Mass Source

Laser induced broadband white emission of Y2Si2O7 nanocrystals

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Journal of Rare Earths 2019年第11期37卷 1196-1199页

作者： Robert Tomala dariusz Hreniak Wieslaw Strek Institute for Low Temperature and Structure Research Polish Academy of Sciences

The generation of broadband white emission of theα-Y2Si2O7 nanocrystals was observed upon excitation by focused beam ofCW lasers operating in near infrared,visible and blue *** influence of excitation energy on order of process is *** temperature of sample emitting laser induced white emission(LIWE)was determined by luminescence nanothermometry *** is found that the temperature is much lower than that predicted by blackbody model characterized with the same *** is shown that the LIWE is accompanied by efficient *** origin of white emission is discussed in terms of multiphoton ionization process leading to the inter valence charge transfer emission.

关键词： White light Photoconductivity Laser induced emission Nanocrystals

Measurements of Water-Air Flow Phenomena in a Chamber with a Rotating Shaft

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Journal of Thermal Science 2021年第1期30卷 242-247页

作者： TIUTIURSKI Paweł HERCEL Paulina TELEGA Janusz KARDAŚdariusz Flow and Combustion Department Renewable Energy FacultyInstitute of Fluid Flow Machinery Polish Academy of SciencesFiszera 1480-231GdańskPoland Flow and Combustion Department Experimental Aerodynamics FacultyInstitute of Fluid Flow Machinery Polish Academy of SciencesFiszera 1480-231GdańskPoland

The paper concerns the phenomena of the fluid film that occurs in the bearing chamber of an aircraft *** geometry of the system includes two concentric cylinders,between which there is a mixture of oil and *** fluid circulates in a closed *** rotary movement of the inner cylinder causes creation of the fluid film on the walls of the *** article proposes a measurement method that is allowing observation of this fluid film and,in particular,analysis of the movement of the air bubbles occurring in the *** own model of the bearing chamber with transparent walls was constructed for the *** the investigation,water was used instead of *** of the behaviour of the flow was possible thanks to video recordings made with the use of a fast-capture *** results presented in the paper include velocity magnitudes of the air bubbles in the fluid film in dependence on the rotational speed of the shaft and water volume fraction and with a range from 0.37 to 0.91 m/*** results presented in this article can be used for the bearing chamber numerical models validation.

关键词： bearing chamber measurements fluid film velocity two-phase flow