The Effect of Disc Radius on Heat Flux and Temperature Distribution in Friction Clutches

2012 ◽  
Vol 505 ◽  
pp. 154-164 ◽  
Author(s):  
Oday Ibraheem Abdullah ◽  
Josef Schlattmann
Keyword(s):  
Heat Flux ◽  
Numerical Calculation ◽  
Thermal Stresses ◽  
Outer Radius ◽  
Accurate Estimation ◽  
Friction Materials ◽  
Machine Element ◽  
Friction Clutch ◽  
Proper Design ◽  
Friction Surfaces

Friction clutch is an important machine element, which transmits the torque from the engine to the gearbox. Hence, an accurate estimation of the heat flux and temperatures on the friction surfaces is essential for proper design of the clutch to avoid failure due to thermal stresses. The dimensionless radius ratio (R=inner disc radius/outer disc radius) is the main key quantifying the quantities of heat flux and temperature on friction materials of clutch. Furthermore, the effect of (R) on the axial force, inner and outer radius, peripheral velocity and torque is investigated as well. The MATLAB and ANSYS have been used to perform the numerical calculation in this paper.

Thermo-Fluid-Stress-Deformation Analysis of Two-Layer Microchannels for Cooling Chips With Hot Spots

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Abas Abdoli ◽  
George S. Dulikravich ◽  
Genesis Vasquez ◽  
Siavash Rastkar
Keyword(s):  
Heat Flux ◽  
Thermal Stresses ◽  
Hot Spot ◽  
Heat Removal ◽  
High Heat ◽  
Heat Transfer Analysis ◽  
Deformation Analysis ◽  
High Heat Flux ◽  
Cooling Design ◽  
Microchannel Cooling

Two-layer single phase flow microchannels were studied for cooling of electronic chips with a hot spot. A chip with 2.45 × 2.45 mm footprint and a hot spot of 0.5 × 0.5 mm in its center was studied in this research. Two different cases were simulated in which heat fluxes of 1500 W cm−2 and 2000 W cm−2 were applied at the hot spot. Heat flux of 1000 W cm−2 was applied on the rest of the chip. Each microchannel layer had 20 channels with an aspect ratio of 4:1. Direction of the second microchannel layer was rotated 90 deg with respect to the first layer. Fully three-dimensional (3D) conjugate heat transfer analysis was performed to study the heat removal capacity of the proposed two-layer microchannel cooling design for high heat flux chips. In the next step, a linear stress analysis was performed to investigate the effects of thermal stresses applied to the microchannel cooling design due to variations of temperature field. Results showed that two-layer microchannel configuration was capable of removing heat from high heat flux chips with a hot spot.

Paper 16: Friction in Wet Clutches

1967 ◽  
Vol 182 (14) ◽  
pp. 132-138 ◽  
Author(s):  
E. M. Evans ◽  
J. Whittle
Keyword(s):  
Coefficient Of Friction ◽  
Power Transmission ◽  
Sliding Speed ◽  
Friction Materials ◽  
Friction Characteristics ◽  
Sliding Surfaces ◽  
Base Oils ◽  
Wet Friction ◽  
Friction Clutch ◽  
The Coefficient Of Friction

This paper is intended to demonstrate that designers of wet clutches for power transmission can obtain the optimum friction characteristics for specific applications by considering the interaction between friction materials and lubricants. A friction clutch plate rig is described and the friction results obtained are presented. It is shown that a wide variation of coefficients of friction and frictional characteristics in wet friction clutches can be obtained by changing the oils and friction materials. In particular the coefficient of friction is dependent upon (1) the oil, (2) the materials of the sliding surfaces, (3) sliding speed, and (4) temperature. It is also shown that the coefficient of friction is affected by ( a) refining treatment given to the oil, ( b) different base oils, and ( c) additives.

Heat Flux Distribution Over a Solar Central Receiver Using an Aiming Strategy Based on a Conventional Closed Control Loop

2017 ◽  
Author(s):  
Jesús García ◽  
Yen Chean Soo Too ◽  
Ricardo Vasquez Padilla ◽  
Rodrigo Barraza Vicencio ◽  
Andrew Beath ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flux Distribution ◽  
Thermal Stresses ◽  
Control Strategies ◽  
Multiple Input Multiple Output ◽  
Control Loop ◽  
Heat Flux Distribution ◽  
Input Multiple Output ◽  
Solar Receiver ◽  
Solar Field

Solar thermal towers are a maturing technology that have the potential to supply a significant part of energy requirements of the future. One of the issues that needs careful attention is the heat flux distribution over the central receiver’s surface. It is imperative to maintain receiver’s thermal stresses below the material limits. Therefore, an adequate aiming strategy for each mirror is crucial. Due to the large number of mirrors present in a solar field, most aiming strategies work using a data base that establishes an aiming point for each mirror depending on the relative position of the sun and heat flux models. This paper proposes a multiple-input multiple-output (MIMO) closed control loop based on a methodology that allows using conventional control strategies such as those based on Proportional Integral Derivative (PID) controllers. Results indicate that even this basic control loop can successfully distribute heat flux on the solar receiver.

scholarly journals Contact Analysis of a Dry Friction Clutch System

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Oday I. Abdullah ◽  
Josef Schlattmann
Keyword(s):  
Pressure Distribution ◽  
Contact Stiffness ◽  
Load Condition ◽  
Accurate Estimation ◽  
Factors Affecting ◽  
Clutch System ◽  
System Pressure ◽  
Friction Clutch ◽  
Contact Surfaces ◽  
Dry Friction Clutch

The numerical simulation of the friction clutch system (pressure plate, clutch disc, and flywheel) during the full engagement period (assuming no slipping between contact surfaces) is carried out using finite element method. Two types of load condition considered affect on the clutch elements during the full engagement period are the contact pressure of diaphragm spring and the centrifugal force. The study of the pressure distribution between the contact surfaces and the factors affecting it is one of the fundamentals in the process of designing the friction clutch to obtain accurate estimation of the temperature distribution during the slipping period and the contact stresses during the full engagement period. The investigation covers the effect of the contact stiffness factor FKN on the pressure distribution between contact surfaces, stresses, and penetration. The penalty and augmented Lagrange algorithms have been used to obtain the pressure distribution between contact surfaces. ANSYS13 software has been used to perform the numerical calculation in this paper.

The synergistic effect of carbon materials on properties of copper-based friction materials

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lin Xueyang ◽  
Liu Rutie ◽  
Wang Lin ◽  
Li Zhengzhou ◽  
Xiong Xiang ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Peer Review ◽  
Petroleum Coke ◽  
Carbon Materials ◽  
Metal Sulfide ◽  
Reduction Process ◽  
Friction Materials ◽  
Content Type ◽  
Braking Process ◽  
Friction Surfaces

Purpose This study aims to investigate the effect of combined use of granular graphite and petroleum coke on the properties of copper-based friction materials and the friction and wear mechanisms. Design/methodology/approach Copper-based friction materials with different proportions of petroleum coke and granular graphite were prepared by using powder metallurgy. The friction surfaces were analyzed. Findings Changing the ratio of petroleum coke/granular graphite affects the formation of oxides and sulfides on the surface of the materials. Increasing the petroleum coke promotes the production of metal sulfide and sulfate in the friction materials and reduces coefficient of friction (COF) and wear. Increasing petroleum coke also increases the amount of carbonic oxide (CO) released during the braking process and promotes the reduction process of iron oxide on the friction surface. Originality/value The synergistic effect of carbon materials on copper-based friction materials was studied in terms of the tribological chemical reaction. This research provides useful information for the selection of carbon materials in friction materials. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0075/

FINITE ELEMENT ANALYSIS OF THE THERMAL BEHAVIOUR OF SINGLE-DISC CLUTCHES DURING REPEATED ENGAGEMENTS

Tribologia ◽  
2016 ◽  
Vol 266 (2) ◽  
pp. 9-24 ◽  
Author(s):  
Oday I. ABDULLAH ◽  
Laith Abed SABRI ◽  
Wassan S. Abd Al-SAHB
Keyword(s):  
Finite Element ◽  
Thermal Behaviour ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Finite Element Models ◽  
Element Analysis ◽  
Premature Failure ◽  
Friction Clutch ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Most of the failures in the sliding systems occur due to the high thermal stresses, which generated at the interface between the contacting surfaces due to sliding between parts, such as friction clutches and brakes. In this paper, the thermal behaviour of a single-disc clutch is investigated. The surface temperatures of the friction clutch disc will be increased during repeated engagements, in some cases, will lead to premature failure of the clutch disc. In order to avoid this kind of failure, it the surface temperature should be calculated with high accuracy to know the maximum working temperature of the friction system. In this work, the temperature distributions are computed during four repeated engagements at regular intervals (5 s) for the same energy dissipation. Three-dimensional finite element models are used to simulate the typical friction clutch disc.

NUMERICAL AND FINITE ELEMENT CONTACT TEMPERATURE ANALYSIS OF FRICTION MATERIAL ’S TYPE EFFECT ON A THERMAL TRANSIENT BEHAVIOR OF A SINGLE-DISC DRY CLUTCH

Tribologia ◽  
2018 ◽  
Vol 271 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Majid Habeb FAIDH-ALLAH
Keyword(s):  
Finite Element ◽  
Transient Behavior ◽  
Friction Material ◽  
Sliding Velocity ◽  
Friction Materials ◽  
Clutch System ◽  
Friction Clutch ◽  
Dry Clutch ◽  
Element Technique ◽  
Contact Temperature Analysis

The sliding period is considered a critical period in the lifetime of friction clutches, because most failures occur during this period. High temperatures due to sliding velocity will appear on the contacting surfaces of the friction clutch system (e.g., in single -disc clutch are pressure plate, clutch discs and flywheel). The finite element technique has been developed to investigate the effect of the type of friction material (material properties) on the transient thermoelastic behaviour of a single-disc dry clutch. Two types of friction materials are used in this work: organic and sintered friction materials. Axisymmetric models are developed to simulate a friction clutch system (single disc with two effective sides). The results represent the comparisons between organic and sintered friction discs, behaviours during slipping periods in clutches.

Sign in / Sign up

Export Citation Format

Share Document