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1

The temperature and stress field of the ceramic-capped cylinder head of the hypothetical adiabatic diesel engine

Jaskólski J., Krzyżak R.

Journal of KONES

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2008

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Vol. 15, No. 4

635-640

EN

Four of five models of the ceramic-slab-capped cast-iron cylinder head for a prospective adiabatic engine were numerically investigated. The models were designed using several crystallochemical-mineralogical considerations. The outcome of some short radiation and convection Fortran95 programmes became the input data for the FEM programme of temperatures and stresses. It turns out, that in general the material that cannot withstand will hardly be ceramics, but the cast iron. Thence, the latter should be replaced, plated or the ceramics should cover it at the injection jet. The temperatures and stresses were analysed with and without an interlayer. Two models, with feldspars and Ti6Al4V or Pt30Au70, were quite promising, the first one being surely at once applicable even without interlayer i.e. according to FEM. The stresses in the models with YSZ, cerium disilicide and/or pyroxene, in spite of the crystallochemical hattrics deemed successful, betoken spallation of the YSZ. The problems of emissivity were addressed as well. There exists a blank range of temperature where neither radiation-related algorithm nor the common conductivity one can perform well. The surface of the head under hood appears 'quite cold', except the exhaust pipe, the TBC solution of which is left in abeyance in this paper. Adiabatic engines using ceramic as the material for the combustion camber walls were developed for the reduction of cooling loss and the in crease of exhaust energies.

2

The temperature - and stress fields of valves of IC engine

Jaskólski J., Krzyżak R.

Journal of KONES

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2007

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Vol. 14, No. 3

245-252

EN

The paper concerns building up one exhaust valve of composite-steel and two intake ceramics-steel valves of a hypothetical adiabatic engine. The input temperatures were computed using three diverse FORTRAN95 programs, solving a shortened optical integral equation with radiative transfer, transient differential equation while starting and switching off the engine and a rod like diff. Equation with 'progonka' (Thomas) solution. The ANSYS11 programme was fed up with the output of the programs. It turns out that, generally, a mineralogical, crystal-chemical approach to the joining of materials results in stresses known from the common metal engines. Such problems as CTE enhancing (partly hypothetical) by means of doping the anionic compounds by cationic ones, swelling of structures, compressibility versus coefficient of thermal expansion (CTE) , compatibility of crystal motifs while joining, thermal shock resistance, switching the bonds, mechanical longevity, radiation protection etc were addressed. It turns out that true nature of the temperature and stress field, especially of the exhaust valve is closer to the FORTRAN temperature computation than, e.g. From the heat film coefficients (ANSYS11).

3

A thermomechanical aspect of the ceramic-capped piston of hypothetical adiabatic diesel engine

Jaskólski J., Krzyżak R.

Journal of KONES

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2006

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Vol. 13, No. 2

169-177

EN

The paper concerns a hypothetical Al.-alloy piston coated (capped) first by labradore and then capped by YSZ. The labradore, a member of the feldspar group is deemed thermal-shock resistant, the YSZ(PSZ) can be shock-resistant, but the outcome of the two with the Al.-alloy is not known. The analysis were made in two ways by ANSYS 10.0, as wholly isotropic materials and (second) labradore treated as wholly orthotropic one as basing on a designed texture. The above programme was fed up by the FORTRAN95-outcome of temperatures and the other B.C.’s.The temperatures between the ceramics and the alloy (except one node!!, the FORTRAN) are ( from the above two procedures), 222.63 to 270-300 graduate C, at the first groove are about 290 graduate C, and, surely lower (orthotropic). The relatively low (to ceramic) inner tensile stresses are embraced by the compressive ones from all the sides. The only problem is the-alloy bearing capacity at some sections at the ceramic boundary (and only there). But, it was the aim of the work to stick ceramics there.The dangerous stresses can occur at the pin .The ‘orthotropic ‘ results are better than the ‘iso’-ones and more true.. Taking into account that the real loading will be lower (porosity of the ceramics, the mass and the possible subtraction of stresses, i.e. those ceramic-production-confined ones) , the laboratory production of the piston appears worth.

4

Some novel materials for combustion engines

Jaskólski J., Krzyżak R.

Journal of KONES

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2005

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Vol. 12, No. 1-2

147-151

EN

A review of a few ceramic materials and mainly minerals, being hypothetically prospective materials for bond coat (BC) and, partly, the thermal barrier coating, TBC of the engine parts is given. It turns out that several framework silicates can be prospective materials as BC for Al.- alloys, whereas sorosilicates should match properties of the alloyed steel. The joining prospects of some materials as feldspars, yttria, pyrochlore and perovskite were partly addressed in the earlier author(s)’ papers, and are mentioned. Apart from mechanical properties, coefficient of thermal expansion as well as crystallisation force of the phases under consideration, rules of epitaxy as well as symmetry-energy problems are addressed. Finally, several synthetic phases are mentioned and their prospective character as BC – indicated.

5

The Ag-Cu sulpho-tellurides and tellurides from Hovin, Telemark, Norway

Krzyżak R.

Rudy i Metale Nieżelazne

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2004

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R. 49, nr 6

280-282

EN

Two minerals (phases) of diverse origin are described here. The first one, Ag3.50Cu0.56Te0.98S0.96, with the ideal formula, Ag3.5Cu0.5TeS, occurs in chalcopyrite of metabasites along with hessite, being a metamorphic mineral. Its optical properties mimic those of hessite. It seems to be a known mineral. The second one, Ag3.97Cu0.43Te2, or simply (Ag, Cu)Sigma 9 Te4, or, Ag4Cu0.5Te2 occurs in chalcocite of the boronite-chalcocite intergrowths of quartz-muscovite-calcite veins of apo-metamorphic, hydrothermal character. Its optical properties are close to those of tetradymite. It is coevel or replacing chalcocite, being an integral part of this late mineralisation. Owing to small grains of the minerals, the description is of preliminary character. Larger grains are needed to establish the latter as a new mineral.

PL

Opisano dwie fazy mineralne (minerały) różnego pochodzenia. Pierwsza, o wzorze: Ag3,50Cu0,56Te0,98S0,96 (idealnie: Ag3,5Cu0,5TeS), występuje wraz z hessytem w chalkopirycie metabazytów i jest pochodzenia metamorficznego. Optycznie przypomina hessyt i wydaje się być znanym minerałem. Druga to: Ag3,97Cu0,43Te2 (albo po prostu (Ag, Cu) Sigma 9 Te4 czy Ag4Cu0,5Te2), występująca w chalkozynie przerostów boronitowo-chalkozynowych hydrotermalnego, postmetamorficznego pochodzenia (żyły kwarcowo-muskowitowo-kalcytowe). Optycznie jest podobna do tetradymitu. Zastępuje chalkozyn lub też jest z nim równoczasowa w tej późnej mineralizacji. Z uwagi na małe ziarna opisywanych faz opis ma charakter wstępny. Jeśli ta druga faza ma zaistnieć jako nowy minerał - konieczne są większe ziarna.

6

An account to the mineralogy of Re-bearing phases

Krzyżak R.

Rudy i Metale Nieżelazne

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2004

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R. 49, nr 8

398-399

EN

The up-to-date mineralogy of Re is somewhat different from that frequently presented in the world-wide-known literature, and namely the contemporary formula of dzhezkazganite is ReMoCu2PbS6. Besides, native Re, a Re amount of Cu-Mo-S-, Cu-Mo-As-S-, crichtonite-senaite mineral groups and anhydrite is well konown. A Re-bearing galena-like phase, with Re amount of about 3,0 wt. %, was encountered in Hovin, Telemark, Norway. This phase mainly occurs with bornite, galena and chalcopyrite, being a part of this metamorphosed assemblage. The pre-metamorphic assemblage must have been 'saturated' with Re (high isomorphic capacity).

PL

Aktualna mineralogia minerałów renu jest nieco odmienna od często prezentowanej w znanej literaturze. Wzór dżezkazganitu brzmi obecnie ReMoCu2PbS6. Dobrze znane jest ponadto występowanie renu rodzimego oraz to, iż takie grupy mineralne jak Cu-Mo-S, Cu-Mo-As-S, krichtonitu-senaitu czy też anhydryt zawierają Re. W złożu Hovin (Telemerk, Norwegia) znaleziono galenopodobny minerał z zawartością Re około 3,0% wagowo. Minerał ten jest częścią zmetamorfizowanego zespołu minerałów wraz z boronitem, galeną i chalkopirytem. Pojemność izomorficzna tego zespołu minerałów ze względu na Re przed metamorfizmem musiała być duża.

7

New materials and ideas to be used in adiabatic engines

Jaskólski J., Krzyżak R.

Journal of KONES

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2004

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Vol. 11, No. 1-2

288-294

EN

This note concerns several topics. Firstly, a review of some less-known topics regarding the contemporary knowledge on TBC and piston caps is given. Then, it turns out that almost unknown New Periodic System of Elements can be of assistance to predict several properties of new TBC materials. Theoretically, there exist a possibility to join Si-AL-piston alloy with yttria-stabilised zirconia (and the like) by means of feId spars (plagioclase). The latter do not attain to melting temperature and can be arrested within the alloy. A shortened integral optical equation in the manner of inverse problem was used to compute the temperature drop accros the piston cap's layers. The YSZ layer operating in this hypothetical engine gave 517.5 graduate K drop, whereas the feldspar gave about 100-50graduate K temperature drop per mm. This arrangement would give minimised radiation and more or less 'cold' engine(piston). Perhaps, oxides of the thalium-sesquioxide-type structure would be better to stick to metal than the commonly used ones.