CFD of Thermal System for Euro VI Bus Engine

The Wrights Group Ltd. produces the most fuel efficient single and double deck buses in the UK. Over the past four years, WrightBus have focused on improving conventional vehicle fuel economy. The high demand for more environmentally friendly vehicles has led to the introduction of more complex engine system technologies. In fact, the vehicle's power unit transitions from a single form of vehicle propulsion based on internal combustion engine (ICE) toward a hybrid system that includes more electrical components.

A significant factor in continuing to improve fuel economy is to gain a deeper understanding of the vehicles thermal management. Vehicle thermal management systems are critical in terms of safety, reliability, performance and passenger comfort. To meet current and future emissions standards, the aftertreatment systems must be maintained above a certain temperature. Currently falling below this temperature requires fuel to be combusted within the aftertreatment system. This amounts to a significant fuel economy penalty.

There is now a need for a complete and detailed CFD model of the engine thermal system of a mild hybridised conventional bus. Such a model can be used to evaluate thermal and therefore fuel economy performance in a simulated driving environment.

The aim of this project is to develop a numerical model which is able to investigate the details of the heat transfer characteristics and thermal system in a Euro VI bus engine to achieve an optimum thermal management strategy.
The model would essentially see the powertrain broken down into elements that would enable us to predict the hot spots in the engine components the engine bay. Valuable information achieved by the analysis of each of the main components will be used to investigate the relevance of the thermodynamic systems placed in the underhood. The model will be tested in various driving and environmental conditions.

This project involves working closely with the Thermal Analysis team within the Wrights Group Technical Centre at QUB and with the development team at Wrights Group Ltd. to create and validate the model. The model will then be used to optimise the control strategy and to plan for future product development within the long term fuel economy technology road.