International Journal of Vehicle Structures and Systems

K. R. M. Mahmoud ¹, M. A. Mourad ¹

Affiliations
1 Mechanical Engineering Dept., Minia University, EG

Abstract

In this work, laboratory tests have been carried out to investigate the influence of the presence of water and oil film, as well as the existence of wet dust between the disc and brake pads on the performance characteristics of conventional and wedge disc brakes are examined. The number of brake application and its influence on friction at dry and wet conditions are also investigated. The results indicated that the presence of a water layer between brake pads and disc led to increased friction coefficient and therefore increased the brake shoe factor. The presence of oil film between the friction surfaces lead to obvious reduction in the coefficient of friction. The influence of the presence of wet dust between the friction surfaces has a negligible influence on both conventional and wedge disc brakes.

Keywords

Wedge Disc Brake, Braking System, Coefficient of Friction, Brake Shoe Factor, Sliding Speed.

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M. F. Ezzat ¹, M. A. Mourad ¹, M. M. Yousef ¹

Affiliations
1 Mechanical Engineering Dept., Minia University, EG

Abstract

The static friction force increases for an increase in the tangential displacement up to the value that is necessary to initiate gross-sliding of the bodies in contact. The static friction coefficients of tyre tread of different strength properties under varying contact conditions are investigated. Smooth surfaces were considered to evaluate the effects of roughness on adhesion of tyre treads. In this investigation different types of road surfaces were tested. The results show that larger tread contact resulted in higher coefficients of static friction. The static friction coefficient decreased for an increase in the tyre tread stiffness. The static friction coefficient decreased for an increase in the surface roughness, then passes through a minimum and finally increased for higher roughness of the counter face. The effect of contaminants such as water, fuel and lubricant between head and counter face were also investigated.

Keywords

Static Friction Coefficient, Tyre Tread, Contact Pressure, Road Surface Roughness, Contamination.

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O. Y. Abdelfattah ¹, M. A. Mourad ¹, I. M. Youssef ¹, S. R. Allam ², A. M. Abd-El-Tawwab ¹

Affiliations
1 Mech. Engg. Dept., Minia University, EG
2 Automotive Tech. Dept., Helwan University, EG

Abstract

This research aims to enhance the performance characteristics of diesel engine fuelled with biodiesel produced from waste cooking oils. The effects of fuel injection pressure (IP) on the performance characteristics of diesel engine and emission pollutants are investigated through experimental works using one cylinder diesel engine, direct injection using conventional petroleum diesel and two biodiesel blends (B5) from waste oil i.e. palm and sunflower oil. Five different IPs 100, 110, 130 and 140 kg/cm², were used besides the original IP of 120 kg/cm². Performance characteristics of diesel engine such as brake power, brake specific fuel consumption and exhaust emission such as CO, CO₂, HC, NO_x and PM have been measured while the engine speed is ranged from 1500 to 3500rpm and constant load (65%). The results showed a significant enhancement of the performance of diesel engine fuelled with biodiesel at an IP of 130 kg/cm².

Keywords

Biodiesel Fuel, Pressure of Fuel Injection, Engine Performance, Emission Characteristics.

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