Turbulent burning velocities have been measured in an explosion bomb equipped with four high speed fans. Turbulent parameters were measured by laser doppler anemometry. The turbulent Reynolds numbers were significantly higher than in most previous measurements and high rates of strain were achieved until, ultimately, several of the flames quenched. Results are presented in terms of previously used dimensionless parameters plus a Lewis number and a dimensionless activation energy. The two-eddy theory of burning can allow for flame straining reductions in laminar burning velocity and experimental values of u t / u 1 were compared with those from such a theory.

In this research, an experimental setup was built based on using K-type thermocouples inserted in a cylindrical vessel and coupled with a computer system to enable online reading of flame speed for propane-air mixtures. The work undertaken here has come up with data for laminar burning velocity of the propane-air mixtures based on three initial temperatures T u = 300, 325 and 350 K, three initial pressures p u = 0.5, 1.0 and 1.5 bar over a range of equivalence ratios f between 0.6 and 1.5. The results obtained gave a reasonable agreement with experimental data reported in the literature. Results showed that laminar burning velocity increases at low initial pressures and decreases at high pressures, while the opposite occurs incase of temperatures. The maximum values of the laminar burning velocity occur at T = 350 K, p u = 0.5 and f = 1.0, respectively, while the minimum values of the laminar burning velocity occur at T = 300 K, p u = 1.5 and f = 1.2. Also, the influence of flame stretching on laminar burning velocity was investigated and it was found that stretch effect is weak since Lewis number was below unity for all cases considered. Based on experimental results, an empirical equation has been derived to calculate the laminar burning velocity. The values of the laminar burning velocity calculated from this equation show great compatibility with the published results. Therefore, the derived empirical equation can be used to calculate the burning velocities of any gas of paraffin gas fuels in the range of mixture temperature and pressure considered.

No abstract

This current project is carried out at Philadelphia University and describes the work associated with the design, build, and test a Formula Student racing car in order to compete at Formula Student competition at UK 2014. Following the Formula Society of Automotive Engineers regulations 2014, 1 this car must be a single seat car with an engine displacement not exceeding 610 cc. It is important to recognize that the design of a Formula Student racing car must involve the study of material structure, aerodynamics, suspension dynamics, internal combustion engine, selection of materials, and the requirements for manufacturing. All of these procedures must be followed to reach an optimum design. The challenge to teams is to develop a vehicle that can successfully compete in all the events (static and dynamic) described in the Formula Society of Automotive Engineers rules. This project is considered as an educational, practical, and training exercise on mechanical engineering principles for the undergraduate and graduate students. Also, it is a high performance engineering project for engineering students to acquire design concepts in automotive, engineering skills, and the freedom to express their creativity and imaginations. Finally, this project will develop experience, skills, and professionalism as 'hands on engineers', and hopefully to enhance automotive industry in Jordan.

A numerical and experimental study was conducted for heat transfer enhancement and fluid flow in a constant heatfluxed rectangular wooden duct fitted with two shapes of vortex generators (circular and square). These vortex generators are of the same area and placed at two different locations (X d = 1 cm and X d = 2 cm) ahead of the heater set and for Reynolds number from 32,000 to 83,000. The numerical and experimental results show an enhancement of heat transfer with the presence of vortex generators. This enhancement depends on the shape and location. Also, the numerical results show saving of 27% of the heater power with the presence of vortex generator. The experimental results of temperature distribution, Nusselt number distribution, effectiveness distribution, and pressure drop values of flow over heaters with vortex generators were reported and compared with the flow over heaters without vortex generators. The results show that heat transfer was enhanced by 2.186%-3.75% using circular type, and it enhanced by 1.3%-1.94% using square type. Also, pressure drop at the outlet of the duct increases by 166.7%-400% when using circular vortex generators and increases by 133.3%-300% when using square vortex generators. These values were obtained for the velocity ranging between 4 and 10 m/s and when vortex generators were placed at location X d = 2 cm. Finally, correlation equations for Nusselt number were obtained at location X d = 2 cm ahead of the heater set.

Supersonic single-mode ramjet performance was analyzed using a prescribed two-dimensional conical shock wave in axisymmetric supersonic flow. The ramjet under consideration for the analysis consists of a mixed compression intake, a cylindrical combustion chamber and a supersonic constant convergent-divergent nozzle. A computer program was developed to carry out the analysis based on the formation of multiple conical shock waves at the engine intake at different flight Mach numbers and different altitudes in the range of 1.5-4 Mach and 9000-18,000 m, respectively. Accordingly, a supersonic convergent-divergent nozzle was designed and consequently, the area ratios along the ramjet were calculated to find the correct dimensions for the thrust required. The analysis of the multi-shock system showed that for a given number of conical shocks and Mach numbers, the thrust decreases as the altitude increases. Also, the thrust increases at higher Mach numbers and higher number of conical shocks regardless of the altitude. Furthermore, for M42:5, and at number of conical shocks greater than 2, thrust stays constant. The flow rate and the pressure after combustion showed similar trends as the thrust. The multi-shock system of the intake system proposed showed that a limit of a three conical shocks were sufficient for a reasonable pressure recovery for a M42, while for a M52, a single normal shock wave could be sufficient for different altitudes. Also, pressure recovery is unaffected by the altitude for the same Mach number and increases with lower Mach numbers. Moreover, the increase of number of conical shocks is limited to 3 where no further increase in pressure recovery could be indicated.