Some principles of the development of a fretting-resistant lubricant

Pokhmurskii, V. I.; Bilonoga, Yu. L.; Sirak, Ya. M.; German, N.

doi:10.1007/bf00722252

Cited by 2 publications

(7 citation statements)

References 3 publications

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“…Earlier, in the papers [5][6], we proposed a concept for considering the contacting of metallic surfaces with allowance for the surface energy and of the energy of the bond of the contacting metals. In the work [7] we outlined the basic principles of the development of a wear-resistant semi-liquid lubricant into which soft metal powders with low surface energy values were introduced. The metal powder was used as a soft damping layer and protected the main metal surfaces from rapid wear, and the base was a semi-liquid lubricant [7].…”

Section: The Distribution Hypothesis With Allowance For Surface Forcementioning

confidence: 99%

“…In the work [7] we outlined the basic principles of the development of a wear-resistant semi-liquid lubricant into which soft metal powders with low surface energy values were introduced. The metal powder was used as a soft damping layer and protected the main metal surfaces from rapid wear, and the base was a semi-liquid lubricant [7]. These issues are very important in considering the processes of thermal and fretting corrosion, in particular, anchor bolts and other heavily loaded fretting and friction assemblies [8].…”

Section: The Distribution Hypothesis With Allowance For Surface Forcementioning

confidence: 99%

“…In the work [9], we proposed the same concept as in the works [5][6][7], only for the surface of a metal and a moving fluid. This is the concept of the movement of a fluid near a solid metal wall (coolant flow -tube walls), taking into account surface tension forces, the values of which in an LBL are commensurate with pressure forces and significantly exceed gravity, friction and inertia.…”

Section: The Distribution Hypothesis With Allowance For Surface Forcementioning

confidence: 99%

“…In the work [9], we calculated the corresponding shell-andtube heat exchanger for the classical method, using the criterion equations, Nusselt numbers and a new method, using formulas (2,3,4,5,6,7,8). The calculation error was only 0.05 % [9].…”

Section: The Values Of the Thermal Resistances Of The Various Zones Imentioning

confidence: 99%

“…Using formulas (2,3,4,5,6,7,8), in [9], using the formula (8), we calculated the total heat transfer coefficient of the chosen heat exchanger, having previously calculated the thermal resistances of all zones of coolants flows [9].…”

Section: The Values Of the Thermal Resistances Of The Various Zones Imentioning

confidence: 99%

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The Laws of Distribution of the Values of Turbulent Thermo-physical Characteristics in the Volume of the Flows of Heat Carriers Taking into Account the Surface Forces

Bіlonoga¹,

Maksysko²

2019

IJHT

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The distribution of resistances values of individual thermal zones of coolants flows is analyzed for the example of milk and water in a shell-and-tube heat exchanger, which was calculated and selected by us in the work [11]. It is shown that thermal resistance of turbulent zones of coolants flows is about 37 % of the total thermal resistance of the heat exchange system in this heat exchanger. The specific thermals resistivity the laminar boundary layer (LBL) zones are much larger, but their total thermal resistance is about 1.5 % because of the very small average thickness of these zones. In this case, the method of analyzing the basic dimensions of physical quantities was used. At the same time, we deduced a new dimensionless number Blturb., which shows the ratio of turbulent viscosities or thermal conductivities to the transitional viscosities or thermal conductivities of the individual coolants zones. Formulas for the calculation of turbulent viscosities and thermal conductivities in coolants of are derived and the law of their distribution in the volume of coolant flows in the pipes and the annular space of the shell-andtube heat exchanger is established. It is shown that this law is an analog of the bell-shaped law of the distribution of Reichardt H. and Ludwig H., and the main difference is that the equation of this law derived by us contains the coefficients of surface tension and hydrophilicity of the wetting surfaces and also the values, reflecting the rates of thermal motion of the heat carriers molecules at a given temperature. A complete analysis of longitudinal sections of coolants flows is made using the example of milk and water in a shell-and-tube heat exchanger for their values of turbulent viscosities and thermal conductivities as well as the turbulent numbers Blturb.. It is shown that the most energy-efficient liquid refrigerants can be selected using a turbulent number Blturb..

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Section: The Distribution Hypothesis With Allowance For Surface Forcementioning

confidence: 99%

Section: The Distribution Hypothesis With Allowance For Surface Forcementioning

confidence: 99%

Section: The Distribution Hypothesis With Allowance For Surface Forcementioning

confidence: 99%

Section: The Values Of the Thermal Resistances Of The Various Zones Imentioning

confidence: 99%

Section: The Values Of the Thermal Resistances Of The Various Zones Imentioning

confidence: 99%

See 3 more Smart Citations

The Laws of Distribution of the Values of Turbulent Thermo-physical Characteristics in the Volume of the Flows of Heat Carriers Taking into Account the Surface Forces

Bіlonoga¹,

Maksysko²

2019

IJHT

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A New Universal Numerical Equation and a New Method for Calculating Heat-Exchange Equipment Using Nanofluids

Bіlonoga¹,

Stybel²,

Maksysko³

et al. 2020

IJHT

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This article analyzes the vast material of works devoted to the use of nanofluids in heat exchange equipment. It is proved that the use of the classical theories and equations for calculating the viscosities and thermal conductivities of nanofluids is not correct, since it does not coincide with the experimental results of most independent authors. A model of the chaotic motion of a nanoparticle is presented taking into account surface tension forces in a liquid coolant. The experimental results of the work of Malaysian and Iran authors on the effect of TiO2 nanoparticles with a concentration of 0.5%; 1.0% and 1.5% in the main liquid solution of ethylene glycol (EG) in water in a volume ratio of 40:60% in terms of heat transfer coefficient are compared with our theoretical studies. The results of the experiments presented in: an increase in heat transfer coefficients by 9.72%, 22.75%, 28.92% for 1.5% volume concentration of TiO2 nanoparticles at a coolant temperature of 30℃, 50℃, 70℃, respectively. Our theoretical result: increase in the obtained heat transfer coefficients by 9.79%, 22.22%, 29.09% according to our formulas (9, 10, 15) for calculating turbulent viscosities and thermal conductivities, which takes into account the effect of surface tension forces on the total flow of nanofluids in the channels of heat exchange equipment. A new method for calculating heat exchange equipment using nanofluids is presented, taking into account the action of surface tension forces, as well as predetermining the calculation of turbulent viscosities and thermal conductivity of nanofluids. A theoretical calculations a plate heat exchangers for a technological task performed by classical and new method is presented. Similar results were obtained, which differ by about 0.5 of a percent. The plate heat exchanger was calculated using a new method using TiO2 nanoparticles in water and in a mixture of EG in water in a ratio of 40:60%, as well as when pumpkin vegetable oil was added to milk with the optimal concentration.

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Some principles of the development of a fretting-resistant lubricant

Cited by 2 publications

References 3 publications

The Laws of Distribution of the Values of Turbulent Thermo-physical Characteristics in the Volume of the Flows of Heat Carriers Taking into Account the Surface Forces

The Laws of Distribution of the Values of Turbulent Thermo-physical Characteristics in the Volume of the Flows of Heat Carriers Taking into Account the Surface Forces

A New Universal Numerical Equation and a New Method for Calculating Heat-Exchange Equipment Using Nanofluids

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