scholarly journals Development of Pressure Distribution Model in Ventilation Ducts of the Brake Disc with Forced Cooling

2021 ◽  
Vol 24 (1) ◽  
pp. 19
Author(s):  
A. E. Litvinov ◽  
P. A. Polyakov ◽  
R. S. Tagiev ◽  
N. A. Zadayanchuk ◽  
A. A. Golikov ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Distribution Model ◽  
Brake Disc ◽  
Ansys Fluent ◽  
Ventilation Ducts ◽  
Forced Cooling

В процессе вращения тормозного диска в вентиляционные каналы попадает воздушный поток, который охлаждает нерабочие поверхности тормозного диска. Для увеличения интенсивности теплообмена от нагретых поверхностей нередко используются системы принудительного охлаждения. Основной задачей систем принудительного охлаждения фрикционных узлов является снижение тепловой нагруженности. Теплоотдача от нагретых поверхностей тормозного диска зависит от количества смен охлаждающего воздуха, т. е. от пропускной способности вентиляционного аппарата. Параметрами, которые влияют на пропускную способность вентиляционного аппарата, могут быть как геометрические размеры, так и аэродинамические показатели (входное давление, координаты источника подачи охлаждаемого воздуха и угол его атаки).В статье приводятся теоретические исследования в виде модели распределения давления внутри вентиляционных каналов. Согласно разработанной модели внутри вентиляционных каналов в процессе вращения тормозного диска наблюдается инверсия давления. Это оказывает влияние на наполняемость вентиляционных каналов тормозного диска воздухом, а в дальнейшем – на тепловую нагруженность всего фрикционного узла. Ребро вентиляционных каналов в разрабатываемой модели распределения давления представляется как пластина, помещенная в воздушный поток под некоторым углом атаки. С помощью расчетного метода обосновано заключение о перепаде давления по всей длине ребра перегородки вентиляционного канала. Полученное распределение давления внутри вентиляционного аппарата возможно заменить результирующей силой. В зависимости от направления действия она может быть как вспомогательной силой при торможении, так и силой сопротивления. Направление действия результирующей силы зависит от сектора установки источника принудительной подачи охлаждающего воздуха. Для подтверждения теоретического изыскания о расположении источника подачи охлаждаемого воздуха было проведено компьютерное моделирование в программном модуле ANSYS Fluent. В рамках компьютерного моделирования исследовалось влияние расположения источника потока воздуха на распределение давление внутри вентиляционных каналов тормозного диска. Полученные результаты позволяют говорить о влиянии расположения источника охлаждающего воздуха на распределение давления внутри вентиляционного аппарата тормозного диска. Это подтверждает гипотезу о том, что координаты источника воздуха и угол атаки могут являться параметрами для оптимизации при создании систем принудительного охлаждения. Помимо этого результата компьютерное моделирование в модуле ANSYS Fluent на основании CFD-модели позволило предложить точки приложения результирующих сил относительно длины вентиляционного канала в зависимости от координат расположения источника принудительной подачи воздуха.Теоретические выкладки подтверждаются как расчетным методом с подстановкой исходных данных в модель распределения, так и методом компьютерного моделирования вентилируемого тормозного диска. Результаты исследований могут дать оценку эффективности оптимизации систем принудительного охлаждения с точки зрения установки источника подачи воздуха и распределения давления в радиальных вентиляционных каналах тормозного диска.

Influence of Forced Cooling Criteria on the Pressure Distribution Inside the Curved Ventilation Ducts of the Brake Disc

2021 ◽  
pp. 47-60
Author(s):  
Pavel Polyakov ◽  
Artem Litvinov ◽  
Ruslan Tagiev ◽  
Alexey Golikov ◽  
Nina Zadayanchuk ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Brake Disc ◽  
Ventilation Ducts ◽  
Forced Cooling

Torque Modelling and Experiment in Pelleting Process of Rotated Roll Forming

2012 ◽  
Vol 184-185 ◽  
pp. 609-613
Author(s):  
Kai Wu ◽  
Yu Sun ◽  
Bin Bin Peng
Keyword(s):  
Pressure Distribution ◽  
Powder Material ◽  
Structural Design ◽  
Experimental Results ◽  
Distribution Model ◽  
Roll Forming ◽  
Testing System ◽  
Force Model ◽  
Optimal Structural Design

First the extruding force model of isotropic powder material passing through the die hole in pelleting process was founded, then the pressure distribution model in the extruding areas was built. Based on the two models, the torque model in pelleting process of rotated roll forming was developed. The experiments were carried out on the special designed pellet mill and the wireless torque testing system was used to analysis the torque datum. It is shown the computing datum is very close to the experimental results. The researches are helpful to the optimal structural design, energy consume reduction and proper use of the pellet mill in practice.

scholarly journals WAVE PRESSURE DISTRIBUTIONS ON A U-OWC BREAKWATER: EXPERIMENTAL DATA VS CFD MODEL

2018 ◽  
pp. 15
Author(s):  
Pasquale G. Fabio Filianoti ◽  
Luana Gurnari
Keyword(s):  
Pressure Distribution ◽  
High Performance ◽  
Ideal Gas ◽  
Navier Stokes ◽  
Eastern Coast ◽  
Computational Domain ◽  
Ansys Fluent ◽  
Wave Energy Converters ◽  
Vof Model ◽  
Line Force

U-OWCs are Wave Energy Converters belong in to the family of Oscillating Water Column. The interaction between waves and a U-OWC breakwater produces an unknown pressure distribution on the breakwater wall, due to the motion inside the plant. In order to evaluate the force acting on a U-OWC breakwater produced by regular waves, we carried out an experiment in a 2D numerical flume. The computational domain is equipped by a piston-type wavemaker, in the left extremity side and a U-OWC breakwater on the opposite side. The water-air interaction is taken into account by means of the Volume Of Fluid (VOF) model implemented in the commercial CFD code Ansys Fluent. Both air and water flow fields are assumed to be unsteady and are computed by solving the Reynolds-Averaged Navier-Stokes (RANS) equations. In the numerical model, air is considered as an ideal gas, in order to take into account the compressibility inside the plenum chamber. Results were compared with a theoretical model on a traditional vertical breakwater and experimental results obtained through an experiment directly at sea, off the beach of Reggio Calabria, in the eastern coast of the Straits of Messina (Southern Italy). As observed in the physical experiment at sea, the pressure distribution are strongly influenced by the absorption of the plant. Indeed, in case of high performance of the U-OWC, we found a deformation of the pressure distribution in respect to the theoretical one, especially near the outer opening of the plant. This deformation produces a lower in line force on the structure.

scholarly journals Squeeze Film Dampers Executing Small Amplitude Circular-Centered Orbits in High-Speed Turbomachinery

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Sina Hamzehlouia ◽  
Kamran Behdinan
Keyword(s):  
Pressure Distribution ◽  
Small Amplitude ◽  
High Speed ◽  
Fluid Film ◽  
Distribution Model ◽  
Squeeze Film ◽  
Fluid Inertia ◽  
Inertia Effects ◽  
Squeeze Film Dampers ◽  
Reaction Forces

This work represents a pressure distribution model for finite length squeeze film dampers (SFDs) executing small amplitude circular-centered orbits (CCOs) with application in high-speed turbomachinery design. The proposed pressure distribution model only accounts for unsteady (temporal) inertia terms, since based on order of magnitude analysis, for small amplitude motions of the journal center, the effect of convective inertia is negligible relative to unsteady (temporal) inertia. In this work, the continuity equation and the momentum transport equations for incompressible lubricants are reduced by assuming that the shapes of the fluid velocity profiles are not strongly influenced by the inertia forces, obtaining an extended form of Reynolds equation for the hydrodynamic pressure distribution that accounts for fluid inertia effects. Furthermore, a numerical procedure is represented to discretize the model equations by applying finite difference approximation (FDA) and to numerically determine the pressure distribution and fluid film reaction forces in SFDs with significant accuracy. Finally, the proposed model is incorporated into a simulation model and the results are compared against existing SFD models. Based on the simulation results, the pressure distribution and fluid film reaction forces are significantly influenced by fluid inertia effects even at small and moderate Reynolds numbers.

Numerical study of the ejection properties of a jet flowing into flooded space

2020 ◽  
Author(s):  
A.Yu. Lutsenko ◽  
V.A. Kriushin
Keyword(s):  
Pressure Distribution ◽  
Nozzle Exit ◽  
Software Package ◽  
Numerical Study ◽  
Supersonic Jet ◽  
Underlying Surface ◽  
Ansys Fluent ◽  
Fluent Software ◽  
Underexpanded Supersonic Jet ◽  
Jet Axis

The purpose of the study was to carry out a numerical simulation of the interaction of an underexpanded supersonic jet flowing into a flooded space with a normally located obstacle, and with the underlying surface. We performed the calculations in the ANSYS Fluent software package and presented flow patterns. For the case when the obstacle is located normally to the axis of the jet, we compared the pressure distribution in the radial direction with experimental data and made a conclusion about the changes in the integral load on the wall with a change in the distance to the nozzle exit. For the case when the obstacle is parallel to the jet axis, we presented the pressure distribution along the wall in the plane of symmetry, estimated the relative net force acting on the underlying surface, analyzed the nature of its change at various values of the off-design coefficient, the Mach number on the nozzle exit and the distance to the jet axis.

scholarly journals Investigating the Effect of Balcony Types on the Naturally-Ventilated Buildings

2020 ◽  
Vol 26 (1) ◽  
pp. 74-86
Author(s):  
Elahe Mirabi ◽  
Nazanin Nasrollahi ◽  
Mehdi Dadkhah
Keyword(s):  
Pressure Distribution ◽  
Pressure Difference ◽  
Natural Ventilation ◽  
Air Flow ◽  
Wind Pressure ◽  
Basic Rule ◽  
Ansys Fluent ◽  
Interior Spaces ◽  
Complicated Pattern ◽  
Naturally Ventilated Buildings

Natural ventilation is application of natural drift power of wind. Wind can enter and exit buildings through the openings on facades. Hence, Form of facades can impact the air flow behaviour and consequently natural ventilation because they can change the pressure distribution on facades. Moreover, wind pressure difference between windward and leeward facades of buildings is the most important factor affecting natural ventilation. So, it is worthy to focus on facade details in order to enhance natural ventilation. Particularly, geometrical details of facades such as protrusions and indentations e.g. balconies can be considered effective elements on average pressure distribution on both windward and leeward facades, changing pressure difference between these facades. This difference can drive the air flow towards interior spaces significantly. Although this basic rule has been used by different researchers in order to increase natural ventilation buildings, the most research has been studied buildings with flat facades. Therefore, this study aims to investigate effects of balcony types on the natural ventilation. Three types of balcony are simulated and the wind pressure distribution on the windward and leeward facades are analysed. All these simulations are carried out for normally (perpendicular) and obliquely incident wind. This study is performed with Ansys Fluent 18 for all simulations. The results showed that balcony types can affect the pressure distribution on the windward and leeward facades of buildings, leading to the more or less pressure difference between these two facades. These results show that protrusion (protrusive balcony) can cause more complicated pattern of the wind pressure on facades than the others. Also, Re-entrant balcony causes the more pressure differences between the windward and leeward facades and enhances natural ventilation of buildings more considerably than the protrusive one.

Two-Dimensional Pore Pressure Distribution Model to Evaluate Effects of Shale Semipermeable Membrane Characteristics

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Jia Wei ◽  
Yuanfang Cheng ◽  
Chuanliang Yan
Keyword(s):  
Diffusion Coefficient ◽  
Pressure Distribution ◽  
Pore Pressure ◽  
Effective Diffusion Coefficient ◽  
Early Stage ◽  
Drilling Fluid ◽  
Effective Diffusion ◽  
Solute Diffusion ◽  
Sensitivity Analyses ◽  
Distribution Model

During the drilling of shale formations, drilling fluids can intrude into the wellbore, raise the pore pressure, and lead to wellbore instability. Based on the thermodynamic theory, a new model was established to calculate pore pressure. The model considers the effects of solute diffusion and solution convection and conducts sensitivity analyses. The results show that the drilling fluid activity significantly affects the pore pressure distribution. The pore pressure under high drilling fluid activity will increase rapidly in the early stage. Low drilling fluid activity can effectively suppress the growth of pore pressure. And a low effective diffusion coefficient of solute and a high membrane efficiency also help to reduce pore pressure. Therefore, reducing drilling fluid activity should be conducted in priority in drilling fluid design. Lowering its solute effective diffusion coefficient and increasing its viscosity can also be considered as auxiliary methods.

Effects of Braking Pressure Distribution on Temperature Field and Stress Field During Braking

2019 ◽  
Author(s):  
Xianyu Zeng ◽  
Yu Liu ◽  
Xiandong Liu ◽  
Yingchun Shan ◽  
Yue Zhang ◽  
...  
Keyword(s):  
Temperature Field ◽  
Fatigue Life ◽  
Stress Field ◽  
Pressure Distribution ◽  
Thermal Fatigue ◽  
Driving Safety ◽  
Brake Disc ◽  
Finite Element Software ◽  
Thermal Fatigue Life ◽  
Brake Discs

Abstract The braking performance of the vehicle directly affects the driving safety. Because of the different number of brake pistons and the wear of the brake pads, the distribution of braking pressure will be uneven, which will affect the distribution of temperature field and stress field during braking, then affect the thermal fatigue life of brake discs. Therefore, in this paper, the static tensile and compressive tests of gray cast iron HT200 samples cut from vehicle brake discs are carried out at −25°C, room temperature (25°C) and 500°C, and the stress-strain curves are analyzed to obtain mechanical properties such as strength limit, elastic modulus and so on at the temperature. Based on these parameters, the finite element software ABAQUS is used to simulate the single emergency braking condition. The thermal-structural coupling simulation of brake disc is carried out to study the influences of uneven brake pressure distribution on the temperature and stress fields of brake disc, which lays a foundation for the thermal fatigue life evaluation of brake disc.

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