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1

Hob wear prediction based on simulation of friction, heat fluxes, and cutting temperature

Hrytsay Ihor, Stupnytskyy Vadym

Archive of Mechanical Engineering

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2023

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LXX, nr 2

271--286

EN

Based on comprehensive interrelated mathematical and graphical-analytical models, including 3D cut layers and simulation of contact, strain, force, and thermal processes during gear hobbing friction forces, heat fluxes, and temperature on the teeth of the hob surface are investigated. Various physical phenomena are responsible for their wear: friction on contact surfaces and thermal flow. These factors act independently of each other; therefore, the worn areas are localized in different active parts of the hob. Friction causes abrasive wear and heat fluxes result in heat softening of the tool. Intense heat fluxes due to significant friction, acting on areas of limited area, lead to temperatures exceeding the critical temperature on certain edges of the high-speed cutter. Simulation results enable identification of high-temperature areas on the working surface of cutting edges, where wear is caused by various reasons, and make it possible to select different methods of hardening these surfaces. To create protective coatings with maximum heat resistance, it is advisable to use laser technologies, electro spark alloying, or plasma spraying, and for coatings that provide reduction of friction on the surfaces – formation of diamond-containing layers with minimum adhesion properties and low friction coefficient on the corresponding surfaces.

2

Biophysical Parameters Assessed from Microwaveand Optical Data

Dąbrowska-Zielińska K., Budzyńska M., Kowalik W., Małek I., Gatkowska M., Bartold M., Turlej K.

International Journal of Electronics and Telecommunications

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2012

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Vol. 58, No. 2

99-104

EN

The study has been carried out at Biebrza Wetlands situated in the N-E part of Poland, a NATURA 2000 and Ramsar Convention test site in 2003-2009. It is one of the largest in Europe natural rich biotope with the large amount of unique species of flora and important zone for nesting and wintering for fauna. Data from microwave and optical satellite images and soil-vegetation ground measurements were analyzed to develop methods for monitoring and mapping biophysical parameters. Satellite data applied for the study included: ENVISAT.ASAR, ENVISAT.MERIS, ALOS.PALSAR, ALOS.AVNIR-2, and NOAA.AVHRR data. Optical images were used for classification of wetlands communities and calculation of vegetation index NDVI. Also, latent heat flux has been calculated using NOAA.AVHRR data and meteorological data. Microwave images acquired in different modes (ASAR IS2 and IS6, ALPSR.FBD) and polarizations (HH, HV, VV) were used for assessment and mapping of Leaf Area Index (LAI) and soil moisture (SM) for every habitat classified from optical images. Backscattering coefficient calculated from ALOS.PALSAR HV and ENVISAT.ASAR IS6 VV was applied for assessment of vegetation bio-parameters. Backscattering coefficient calculated from ALOS.PALSAR.FBD HH and ENVISAT.ASAR HH IS2 was used for SM assessment. The study was conducted in the framework of ESA PECS project No 98101 and ESA PI projects: C1P.7389 and AOALO.3742.

3

Heat and salt fluxes in the West Spitsbergen Current area in summer

Piechura J., Osiński R., Petelski T., Woźniak S. B.

Oceanologia

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2002

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No. 44 (3)

307-321

EN

Fluxes of radiation, sensible and latent heat, and fluxes of heat and salt within the upper layer of the ocean were calculated on the basis of measurements carried out in the area of the Norwegian-Atlantic and West Spitsbergen Currents during summer 2000. The sea surface radiation balance was calculated from direct measurements of downward and upward short-wave (solar) radiation, the net radiation fluxes and sea surface temperature. The daily doses of radiation energy reaching and leaving the sea surface were also estimated. To calculate the vertical heat fluxes in the atmospheric boundary layer the bulk parameterisation method was used. In most cases, the calculated heat fluxes were rather low, the average sensible heat flux was c. 10 W m-2, and the latent heat flux about one order of magnitude higher; this is what could be expected in summer. Salt fluxes to the air in the process of aerosol production are very small and can be neglected. In summer the highest quantities of heat and salt are exchanged during mixing with surrounding waters. According to our measurements, Atlantic Water on its northward course from about 70oN to 79oN loses about 100 TW of heat and 900 × 103 kg of salt. We thought it could be interesting to find out what happens to them. Some preliminary results of our investigation are presented here.

4

Strumienie ciepła przejmowanego w poziomym gruntowym wymienniku pompy grzejnej

Fic A., Hanuszkiewicz-Drapała M.

Chłodnictwo : organ Naczelnej Organizacji Technicznej

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2002

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R. 37, nr 6

8-13

PL

W pracy przedstawiono termodynamiczno-przepływowe aspekty działania poziomego gruntowego wymiennika ciepła pompy grzejnej. Po określeniu postaci pola temperatury w gruncie w rejonie rur wymiennika wyznaczno strumienie ciepła przejmowanego od gruntu przez czynnik pośredniczący w rurach wymiennika. Zbadano obliczeniowo, jaki wpływ na te strumienie ma położenie rur wymiennika, temperatura początkowa i pojemność cieplna strumienia czynnika pośredniczącego, zawartość wilgoci w gruncie oraz warunki wymiany ciepła na zewnętrznej górnej powierzchni gruntu.

EN

Some flow-thermodynamic problems of operation of horizontal ground beat exchanger of beat pump system are presented in the paper. First, the temperature distributions in the ground in the region of ex-changer were determined. Next, the beat fluxes transferred from the ground by intermediate agent inside the tubes were calculated. The calculations have been performed for different values of pipe location, initial temperature and beat capacity of intermediate agent, different contents of moisture in the ground, as well as for various beat transfer conditions on the outer upper surface of the ground.