Modelling the thermal state of a turbocharger bearing housing when calculating the rotor dynamics at transient modes

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Elena Zadorozhnaya ◽  
Vladislav Hudyakov ◽  
Elizaveta Polyacko ◽  
Igor Dolgushin

Purpose The reliability of various mechanisms and machines is determined by the durability of tribo-units, which must ensure operation at high temperatures and an extended range of rotor shaft speeds. The best performance of the bearing assembly is achieved with hydrodynamic lubrication, which depends on optimal operating conditions and temperature conditions. The purpose of this paper is determining the thermal state of the turbocharger (TCR) bearings. Design/methodology/approach The simulation was carried out in the ANSYS Fluent software package. The boundary conditions for the calculation were obtained from experimental data. The experiments were carried out at a specialized stand created at the scientific and production association “Turbotekhnika”. Findings The result of the simulation was the determination of temperatures and thermal fields in the TCR housing. The data obtained testify to the uneven thermal loading of the bearings. When calculating the dynamics of the rotor, transient modes are considered. The results are the trajectories of the rotor in the space of the bearing clearance. The thickness of the lubricating layer was calculated as a parameter that determines the hydrodynamic friction regime. The thermal state of the TCR elements was evaluated at all the considered rotor speeds. The flexible axis of the rotor was obtained at different speeds. Originality/value The paper presents a model of heat transfer in a TCR housing and rotor dynamics, based on numerical methods, which will help in the design of TCRs and journal bearings.

Author(s):  
D. A. Romanyuk ◽  
S. V. Panfilov ◽  
D. S. Gromov

Within the scope of the research work, we have developed the methods and software package for solving the conjugate heat and hydraulic problems based on the classical approach to performing hydraulic calculations and modeling thermal processes by means of the finite volume method in the ANSYS Fluent software package. The developed means allowed us to efficiently calculate the thermal state of complex technical objects. The study gives mathematical formulation of the methods and suggests the results of their approbation and verification


2018 ◽  
Vol 12 (4) ◽  
pp. 4300-4328
Author(s):  
Pasymi Pasymi ◽  
Y. W. Budhi ◽  
A. Irawan ◽  
Y. Bindar

Flow structure inside a chamber greatly determines the process performances. Therefore, the flow structure inside a chamber are often constructed in such a way as an effort to obtain equipment performances in accordance with the expectations. This study explored flow structure inside several chamber geometries and operating conditions. Three types of chamber, namely; GTC, DTC and TJC were set as the investigated chambers. The Computational Fluid Dynamics technique, supported by some experimental data from the literature, is used as an investigation method. The RANS based models, under Ansys-Fluent software were used in this numerical investigation. Simulation results revealed that the flow structures of GTC and DTC are predominantly created by spiral and vortex patterns. The vortex stabilizer diameter in the GTC affects the vortex pattern, velocity profile and pressure drop. The flow structure of DTC presents the most complex behavior. The flow structure inside TJC, in the case of unconfined outlet boundary, is characterized by the helical and wavy jet pattern. This structure is determined by the initial tangential intensity (IIT) and the inlet aspect ratio (RIA). The structures of vortex, helical, and wavy axial flow are properly constructed and visualized in this paper. There is no a turbulence model which is always superior to the other models, consistently. The standard k-ε model exhibits the realistic and robust performances among  all of investigatied cases.


Author(s):  
Cesar Martin Venier ◽  
Andrés Reyes Urrutia ◽  
Juan Pablo Capossio ◽  
Jan Baeyens ◽  
Germán Mazza

Purpose The purpose of this study is to assess the performance of ANSYS Fluent® and OpenFOAM®, at their current state of development, to study the relevant bubbling fluidized bed (BFB) characteristics with Geldart A, B and D particles. Design/methodology/approach For typical Geldart B and D particles, both a three-dimensional cylindrical and a pseudo-two-dimensional arrangement were used to measure the bed pressure drop and solids volume fraction, the latter by digital image analysis techniques. For a typical Geldart A particle, specifically to examine bubbling and slugging phenomena, a 2 m high three-dimensional cylindrical arrangement of small internal diameter was used. The hydrodynamics of the experimentally investigated BFB cases were also simulated for identical geometries and operating conditions using OpenFOAM® v6.0 and ANSYS Fluent® v19.2 at identical mesh and numerical setups. Findings The comparison between experimental and simulated results showed that both ANSYS Fluent® and OpenFOAM® provide a fair qualitative prediction of the bubble sizes and solids fraction for freely-bubbling Geldart B and D particles. For Geldart A particles, operated in a slugging mode, the qualitative predictions are again quite fair, but numerical values of relevant slug characteristics (length, velocity and frequency) slightly favor the use of OpenFOAM®, despite some deviations of predicted slug velocities. Originality/value A useful comparison of computational fluid dynamics (CFD) software performance for different fluidized regimes is presented. The results are discussed and recommendations are formulated for the selection of the CFD software and models involved.


2020 ◽  
Vol 92 (10) ◽  
pp. 1505-1512
Author(s):  
Ahmad Soleymani ◽  
Mehran Nosratollahi

Purpose The purpose of this paper is to simulate the thermal performance of fluidic momentum controller (FMC) actuators in two case, with and without thermal distribution system on a three-axis configuration of FMC actuators to an orbital period of satellite. The results show the effectiveness of using a storage with FMC actuators. Design/methodology/approach One of the challenges during a satellite’s orbital mission is unpredictable external temperature perturbations. This system used as a collaborative thermal subsystem for microsatellite temperature passive control. The operating principles of the system are that each fluid rings are used in a microsatellite surface with pumps to stabilize the satellite. All fluid rings are connected to the satellite thermal distribution system (storage). Findings Simulation results show that with using of thermal distribution system, damping of satellite different surfaces temperature is rapidly possible to the event of thermal disturbances. Practical implications Numerical simulation is obtained by ANSYS Fluent software and pressure-velocity coupling is SIMPLE method and spatial discretization is second order accurate and first order in time, viscous model is k-e. In this regard, a solver algorithm is also developed. Originality/value In space research fields about FMC application as actuators to satellite system design, main goal is to research about role of this system to attitude and determination control system (ADCS) of satellites, and no study is performed on its role to satellite temperature damping. This study is exclusively simulated thermal distribution system (includes a storage and its connections) of a microsatellite equipped with FMC actuators. The idea of using a storage for FMC actuators is the innovative step of this research.


2020 ◽  
Vol 33 (1) ◽  
pp. 27-33
Author(s):  
Sathish Kumar ◽  
Oleg R. Kuzichkin ◽  
Ahmed Faisal Siddiqi ◽  
Inna Pustokhina ◽  
Aleksandr Yu Krasnopevtsev

Purpose This study aims to investigate simultaneous power and thermal loading. Design/methodology/approach Finite element method simulations coupled with experiments. Findings The effects of power cycling have been determined. Originality/value This paper aims to testify the combined effects of thermal and power cycling loads on the reliability of solder ball joints with barrel- and hourglass-type geometries in an electronic system. The finite element simulation outcomes showed that the maximum strain energy was accumulated at the edges of barrel-type solder, whereas the hourglass-type was vulnerable at the necking side. It was also found that the hourglass-type solder showed a reliable behavior when the sole thermal cycling was exerted to the electronic system, whereas the barrel-type solder was a better choice under simultaneous application of thermal and power loadings. The experimental results also confirmed the finite element simulation and indicated that the solder joint reliability strongly depends on the geometry of interconnection in different operating conditions. An extensive discussion was presented to shed light on the paramount importance of combined thermal/power cycling on the reliability of solder joints.


2019 ◽  
Vol 18 (1) ◽  
pp. 55-66
Author(s):  
V. N. Klimov ◽  
D. Ya. Dud’ev ◽  
V. Ya. Sigaylo ◽  
N. I. Klimov ◽  
Yu. K. Mashkov

The article is devoted to the problem of ensuring the operability of air-fuel lubrication and cooling systems for gas turbine engine (GTE) rotor bearings. The paper considers one of the advanced designs of a GTE in which an air-fuel mixture obtained in a special mixer is fed to a bearing installed in the turbine support and then through a hollow shaft to the bearing of the compressor support and then directed to the engine input. It is difficult to implement such a GTE scheme because of the necessity to ensure the operability of bearings lubricated with an air-fuel mixture for a predetermined period of time. It is impossible to determine the thermal state of the bearings and the friction regime in them with sufficient accuracy. The solution of the problems requires carrying out experimental work to determine the coefficients of friction and convective heat transfer in the bearings, as well as their full service life under various operating conditions and parameters of the air-fuel mixture blown through the bearings. The paper presents the results of testing a 45-126205РЯ radial thrust bearing lubricated with an air-fuel mixture, МС-8П oil and a non-lubricated bearing of the same kind. The operability of the GTE rotor bearings lubricated with the air-fuel mixture is analyzed, the area of efficient application of the gas turbine engine with an air-fuel lubrication system is determined.


2018 ◽  
Vol 70 (9) ◽  
pp. 1608-1618 ◽  
Author(s):  
Ali Usman ◽  
Cheol Woo Park

Purpose Journal bearings are used in numerous rotary machines. The load carrying capacity and friction of a bearing have been major concerns in design. Recent developments in surface texturing have showed potential outcomes to improve the tribological characteristics of mating surfaces. This study aims to investigate surface textures, which are transverse to the sliding direction, for frictional response of the journal bearing. Design/methodology/approach A hydrodynamic lubrication model is considered to evaluate the effect of surface texturing on the performance of a journal bearing at varying operating conditions. The two-dimensional generalized Reynolds equation, coupled with mass-conserving Elrod cavitation algorithm, is solved to evaluate texture-induced variations in tribological performance parameters. Findings Results have showed remarkable improvements in frictional response. Moreover, micro-textures on the journal surface alter the cavitation response and film-reformation in the hydrodynamic conjunction of the plain bearing. Originality/value Operating condition-based comprehensive exhaustive optimization of texture geometry is performed to generate widespread conclusion.


2019 ◽  
Vol 7 (1) ◽  
pp. 43-53
Author(s):  
Abbas Jassem Jubear ◽  
Ali Hameed Abd

The heat sink with vertically rectangular interrupted fins was investigated numerically in a natural convection field, with steady-state heat transfer. A numerical study has been conducted using ANSYS Fluent software (R16.1) in order to develop a 3-D numerical model.  The dimensions of the fins are (305 mm length, 100 mm width, 17 mm height, and 9.5 mm space between fins. The number of fins used on the surface is eight. In this study, the heat input was used as follows: 20, 40, 60, 80, 100, and 120 watts. This study focused on interrupted rectangular fins with a different arrangement and angle of the fins. Results show that the addition of interruption in fins in various arrangements will improve the thermal performance of the heat sink, and through the results, a better interruption rate as an equation can be obtained.


Author(s):  
Nguyen Van Liem ◽  
Wu Zhenpeng ◽  
Jiao Renqiang

The effect of the shape/size and distribution of microgeometries of textures on improving the tribo-performance of crankpin bearing is proposed. Based on a combined model of the slider-crank mechanism dynamic and hydrodynamic lubrication, the distribution density, area density, and shape of spherical textures, square-cylindrical textures, wedge-shaped textures, and a hybrid between spherical texture and square-cylindrical texture on the crankpin bearing's tribo-performance are investigated under different operating conditions of the engine. The tribological characteristic of the crankpin bearing is then evaluated via the indexes of the oil film pressure p, asperity contact force, friction force, and friction coefficient of the crankpin bearing. The research results show that the distribution density with n = 12 and m = 6, and area density with α = 30% of various microtextures have an obvious effect on ameliorating the crankpin bearings tribo-performance. Concurrently, at the mixed lubrication region, the shape of the square-cylindrical texture on improving the tribo-performance is better than the other shapes of the spherical texture, wedge-shaped texture, and spherical and square-cylindrical texture. Particularly, all the average values of the asperity contact force, friction force, and friction coefficient with a square-cylindrical texture are significantly reduced by 14.6%, 19.5%, and 34.5%, respectively, in comparison without microtextures. Therefore, the microtextures of the spherical texture applied on the bearing surface can contribute to enhance the durability and decrease the friction power loss of the engine.


2014 ◽  
Vol 703 ◽  
pp. 425-429
Author(s):  
Jun Fei Wu ◽  
Zhi Li ◽  
Fan Guo Meng ◽  
Ben Liang Yu

Compared with traditional screw pump,all-metal screw pump have more advantages in the oil extraction. In this paper, all-metal single screw pump's geometric model was made by PROE software; then the dynamic mesh technique was applied to mesh the model and constraint condition was applied in the ANSYS-FLUENT software. 3D flow field was numerical analyzed In that software, the impacts of screw speed on volume flow and volumetric efficiency were concluded, the conclusion can offer some valuable guidances to the all-metal single screw pump's design.


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