Semiempirical Mathematical Models of Spinning Friction Steel ShKh15 Steel Titles on Steel R6M5, on a Scheme of a Globe Plane Taking into Account Wear

2019 ◽  
Vol 822 ◽  
pp. 701-708
Author(s):  
Alexey Leonidovich Steshenkov ◽  
Sergey Georgievich Chulkin ◽  
Aleksey Aleksandrovich Alkhimenko ◽  
Kirill Yurievich Galskii ◽  
Konstantin Dmitrievich Bogatyrev ◽  
...  

The paper presents the results of the study of the friction of the spherical ball made of steel SHKH15 on the flat surface of the prism of steel R6M5. It has been established that as a result of the friction of the rotation according to the “ball-plane” scheme, at a steady wear mode, the torque of the friction of the rotation also becomes steady. It is shown that the change in the friction torque of the rotation from the load does not fit within the limits of one linear dependence, similar to G. Amonton's law. Semi-empirical models of friction rotation are given.

2021 ◽  
Vol 45 (4) ◽  
pp. 267-272
Author(s):  
Rahmouna Cheriet ◽  
Bourassia Bensaad ◽  
Fatiha Bouhadjela ◽  
Soufyane Belhenini ◽  
Mohammed Belharizi

This study presents a mixed numerical / semi-empirical approach that primarily aimed to estimate the thermal contact resistance between two solids. The results obtained by this mixed method were compared and validated by experimental measurements of this resistance. Three semi-empirical models were used, namely the Mikic model, the Yovanovich model and the Antonetti model. The three-dimensional finite element numerical simulation was used to estimate the contact pressure between the two solids. Then this contact pressure obtained numerically was compared to the hardness of the solids in contact. The findings indicated that the numerically obtained contact pressures were close to hardness. Therefore, the hardness, which is usually used as an input variable in semi-empirical models, was replaced by the contact pressure. The thermal contact resistance obtained by this mixed method was then compared with the experimental one. The outcomes obtained from this comparison turned out to be very conclusive and can therefore be used to reinforce our approach which can actually be viewed as a reliable and low-cost method for estimating the thermal contact resistance between solids in contact.


Author(s):  
Djordje Romanic ◽  
Horia Hangan

Analytical and semi-empirical models are inexpensive to run and can complement experimental and numerical simulations for risk analysis-related applications. Some models are developed by employing simplifying assumptions in the Navier-Stokes equations and searching for exact, but many times inviscid solutions occasionally complemented by boundary layer equations to take surface effects into account. Other use simple superposition of generic, canonical flows for which the individual solutions are known. These solutions are then ensembled together by empirical or semi-empirical fitting procedures. Few models address turbulent or fluctuating flow fields, and all models have a series of constants that are fitted against experiments or numerical simulations. This chapter presents the main models used to provide primarily mean flow solutions for tornadoes and downbursts. The models are organized based on the adopted solution techniques, with an emphasis on their assumptions and validity.


2016 ◽  
Vol 2 (3) ◽  
pp. 460-473 ◽  
Author(s):  
Daniel Gerrity ◽  
Yunho Lee ◽  
Sujanie Gamage ◽  
Minju Lee ◽  
Aleksey N. Pisarenko ◽  
...  

Recent evaluations of potable reuse treatment trains suggest that the use of UV and UV/H2O2may become increasingly common, particularly in systems employing ozone and/or biofiltration.


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