Denis Marchant

A Study of a Multi-Stage Downdraught Evaporative Cooling Device Using CFD to Assess the Effect of the Primary Inlet to Mixing Stack Area Ratio: Preliminary Work to Establish the Baseline Performance of the Device

The aim of the research work described in this paper is to use computational fluid dynamics (CFD) to optimize the geometry of a multi-stage evaporative cooling device to investigate the effects on its performance by varying the primary inlet to mixing st ack area ratio. The studies do not simulate external wind effects or a wind catcher and the ambient air inlet was modelled as an opening. The computational domain was modelled to represent a typical small building having an overall cooled space volume of 1350 m3. The general result suggests that the combined effect of the increased mass flow rate and increased evaporative potential of the incoming air resulted in the observed increase in sensible cooling power.

Enumeration search method for optimisation of stackingsequence of laminated composite plates subjected to buckling

Abstract Enumeration search method (ESM) checks all possible combinations of design variables in a bottom-up approach until it finds the global optimum solution for the design conditions. In this paper an optimum design of a multilayered laminated plate made of unidirectional fibre reinforced polymer (FRP) composite subject to uniaxial compression is sought.ESMtogether with classical laminated plate theory (CLPT) has been used to find the lightest laminate for maximizing the buckling load capable of providing structural stability for a set target uniaxial compression load. The choice of the design variables is limited to 4 possible fibres orientation angles (0,90,-45,+45) and the sequence of the laminate, making the problem an integer programming. Experimental and finite element analyses were used to verify the optimum solution. It has been shown that the exhaustive enumeration search method is a powerful tool for finding the global optimum design.

Investigating the effects on the low speed response of a pressure charged IC engine through the application of a twin-entry turbine housing

In this study, one-dimensional analysis using AVL Boost software has been carried out on a series of compression and spark ignition engines utilizing a manufacturer fitted single-entry turbocharger and a modified twin-entry unit, the latter adopting two symmetrical turbine housing inlet ports. The model reconstruction using AVL Boost considers parameters that accurately represent the physical engine conditions including manifold geometry, turbocharger flow maps and combustion chamber characteristics. Model validations have been made for a standard single-entry turbocharger configuration to predict the maximum engine power and torque, in comparison with available manufacturer data and analytical calculations. Further studies concentrate on engine performance comparisons between single- and twin-entry turbochargers at low engine speed conditions, typically in a range of 1000–3000 RPM. Improvements in turbine shaft speed, engine power and torque have been achieved, thus implying improved low speed engine response. This study reveals the potential commercial benefits of adopting a twin-entry turbocharger and contribution to the academic community through this additional research.

Combustion synthesis of Ni/Al base composites

This paper presents a new ignition technique to synthesize NiAl based composites using high frequency induction heating to ignite the combustion reaction. A high resolution thermal imaging camera and two infrared thermometers were used to monitor the complete temperature profiles during synthesis. Thermodynamic calculations were performed to predict the combustion temperature and the effect of preheating temperatures. The results show that the combustion reaction for Ni/Al based composites can be ignited using a high frequency induction heater. High density, multi layer TiC-NiAl composites can be produced using this method, but to ignite the combustion reaction by induction heating for the Ni/Al+Ti/C system, there is a limit for the content of Ti/C, above which the ignition will not start. Ultra fine TiC was synthesized using this technique.