scholarly journals Airflow simulation when braking with a disc brake

2021 ◽  
Vol 1199 (1) ◽  
pp. 012097
Author(s):  
Y Fomina ◽  
V Pavelčík
Keyword(s):  
Heat Dissipation ◽  
Test Bench ◽  
Air Flow ◽  
Turbulence Models ◽  
Disc Brake ◽  
Specialized Software ◽  
Software Packages ◽  
Brake Discs ◽  
Motion Speed ◽  
Flow Through

Abstract With an increase in train motion speed, the issue of improving braking systems becomes more and more important, since braking systems have a direct impact on safety of traffic. At high travel speeds, the friction elements heat up strongly, so heat dissipation from the brake discs is essential. Therefore, an important task is to study the aerodynamics of brake discs. To achieve these goals, experimental measurements on a special test bench, or simulation in specialized software packages can be used. The article discusses methods for studying air flow when braking with a disc brake. The simulation methods, turbulence models and software packages used for simulation are considered. The influence of the internal geometry of the discs on ventilation and heat dissipation is considered. Also, the geometry of the disc is analysed using simulation in the specialized software. Based on the simulation results, a conclusion about the influence of the internal disc geometry on the air flow through it is drawn.

Experimental Study of Convective Heat Transfer in Standard and Cross-Drilled Brake Discs With Radial Vane and X-Lattice Cores

2018 ◽  
Author(s):  
Hongbin Yan ◽  
Shangsheng Feng ◽  
Wei-Tao Wu ◽  
Tian Jian Lu ◽  
Gongnan Xie
Keyword(s):  
Heat Transfer ◽  
Experimental Comparison ◽  
Brake Disc ◽  
Disc Brake ◽  
Cooling Performance ◽  
Flow And Heat Transfer ◽  
Brake Discs ◽  
Flow Through ◽  
The Cross ◽  
Transfer Mechanisms

To improve the cooling performance of disc brake systems, cross-drilled holes penetrating across the rubbing discs are separately introduced into a commercial radial vane brake disc (as reference) and a novel X-lattice cored brake disc. Prototype samples of both the reference and cross-drilled brake discs are fabricated. A rotating test rig is designed and constructed to characterize and compare the cooling performance of the brake discs with infrared thermography. Within the typical operating range of a vehicle, e.g., 200–1000 rpm, the experimental results show that the introduction of cross-drilled holes can substantially enhance brake disc cooling. For the radial vane brake disc, the overall Nusselt number is enhanced by 31%–44%; for the X-lattice cored brake disc, the cross-drilled holes only lead to 9%–18% enhancement. As the radial vane brake disc and the X-lattice cored brake disc with cross-drilled holes exhibit similar cooling performance, flow through the cross-drilled holes has a more prominent effect on the former than the latter. Corresponding fluid flow and heat transfer mechanisms underlying the enhanced heat transfer by cross-drilled holes and the different effects of cross-drilled holes on the two distinct brake discs are explored. The experimental comparison and the thermo-fluidic physics presented in this paper are beneficial for engineers to further improve disc brake cooling.

3D CFD Investigation of Air Flow Behind a Porous Fence Using Different Turbulence Models

2014 ◽  
Author(s):  
Yizhong Xu ◽  
Mohamad Y. Mustafa ◽  
Geanette Polanco
Keyword(s):  
Velocity Profile ◽  
Turbulence Model ◽  
Air Flow ◽  
Turbulence Models ◽  
Experimental Results ◽  
Turbulence Structure ◽  
Cfd Modelling ◽  
Lack Of Information ◽  
Vertical Velocity Profile ◽  
Flow Through

Even after many years of the application of numerical CFD techniques to flow through porous fences, still there is disagreement between researchers regarding the best turbulence model to be implemented in this field. Moreover, different sources claim to have achieved good agreement between numerical results and experimental data; however, it is not always possible to compare numerical and experimental results due to the lack of information or variations in test conditions. In this paper, five different turbulence models namely; K-ε models (standard, RNG and Realizable) and K-ω models (Standard and SST), have been applied through a 3D CFD model to investigate air flow behind a porous panel, under the same conditions (boundary conditions and numerical schemes). Results are compared with wind tunnel experiments. Comparison is based on the vertical velocity profile at a location 925 mm downstream of the fence along its center line. All models were capable of reproducing the velocity profile, however, some turbulence models over-predicted the reduction of velocity while it was under-predicted by other models, however, discrepancy between CFD modelling and experimental results was kept around 20%. Comprehensive description of the turbulence structure and the streamlines highlight the fact that the criterion for selecting the best turbulence model cannot rely only on the velocity comparison at one location, it must also include other variables.

Research of Window's Discharge Coefficient in the Natural Ventilation Room

2014 ◽  
Vol 525 ◽  
pp. 420-426
Author(s):  
Qi Hai Liao ◽  
Yan Ling Guan ◽  
Qiao Ning Wang
Keyword(s):  
Pressure Difference ◽  
Natural Ventilation ◽  
Discharge Coefficient ◽  
Test Bench ◽  
Air Flow ◽  
Experimental Conditions ◽  
Flow Through

Discharge coefficient of window is one of the important factors in natural ventilated calculation, while there are many factors may impact the windows discharge coefficient. This article adopts the method of experiment, simulate the natural ventilation of room on the test bench , by measuring the pressure difference of both sides of window and the air flow through the window under different experimental conditions, analyze how the opening rate of window and the air flow impact the values of discharge coefficient of window, and giving the value of discharge coefficient of window under the experiment condition, hoping to provide help to the use of natural ventilation of building effectively.

scholarly journals CFD modeling and computation of convective heat coefficient transfer of automotive disc brake rotors -Modelado CFD y cálculo de la transferencia de coeficientes de calor por convección de rotores de freno de disco automotores

2017 ◽  
Vol 2 (29) ◽  
pp. 116
Author(s):  
Ali Belhocine ◽  
Wan Zaidi Wan-Omar
Keyword(s):  
Heat Dissipation ◽  
Air Flow ◽  
Flow Distribution ◽  
Cfd Modeling ◽  
Disc Brake ◽  
Braking System ◽  
Ansys Cfx ◽  
Disc Brakes ◽  
Brake Rotors ◽  
Transient Thermal

Braking system is one of the basic organs to control a car. For many years, the disc brakes have been used in automobiles for safe retardation of the vehicles. During braking, enormous amount of heat will be generated, and for effective braking, sufficient heat dissipation is essential. The specific air flow surrounding the brake rotor depends on the thermal performance of the disc brake and hence, the aerodynamics is an important in the region of brake components. A CFD analysis is carried out on the braking system as the study of this case, to make out the behaviour of air flow distribution around the disc brake components using ANSYS CFX software. The main object of this work is to calculate the heat transfer coefficient (h) of the full and ventilated brake discs as a function of time using the CDF analysis which will be used later in the transient thermal analysis of the disc in ANSYS Workbench 11.0.

CFD Modeling and Simulation of Aeorodynamic Cooling of Automotive Brake Rotor

2018 ◽  
Vol 09 (01) ◽  
pp. 1750008 ◽  
Author(s):  
Ali Belhocien ◽  
Wan Zaidi Wan Omar
Keyword(s):  
Heat Dissipation ◽  
Surface Film ◽  
Transient State ◽  
Cfd Modeling ◽  
Disc Brake ◽  
Cfd Analysis ◽  
Braking System ◽  
Airflow Distribution ◽  
Ansys Cfx ◽  
Brake Rotor

Braking system is one of the important control systems of an automotive. For many years, the disc brakes have been used in automobiles for the safe retarding of the vehicles. During the braking enormous amount of heat will be generated and for effective braking sufficient heat dissipation is essential. The thermal performance of disc brake depends upon the characteristics of the airflow around the brake rotor and hence the aerodynamics is an important in the region of brake components. A CFD analysis is carried out on the braking system as a case study to make out the behavior of airflow distribution around the disc brake components using ANSYS CFX software. We are interested in the determination of the heat transfer coefficient (HTC) on each surface of a ventilated disc rotor varying with time in a transient state using CFD analysis, and then imported the surface film condition data into a corresponding FEM model for disc temperature analysis.

scholarly journals Air flow through a non-airconditioned bus with open windows

Sadhana ◽  
2007 ◽  
Vol 32 (4) ◽  
pp. 347-363 ◽  
Author(s):  
S. R. Kale ◽  
S. V. Veeravalli ◽  
H. D. Punekar ◽  
M. M. Yelmule
Keyword(s):  
Air Flow ◽  
Flow Through
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