Evaporative Cooling of Internal Combustion Engines

The proposed work will examine an evaporative cooling system for use on modern Internal Combustion (IC) engines. The project aims to assess the impact of surface vibration and dynamics on the heat transfer capabilities and stability of controlled evaporative cooling for typical engine coolant jackets. The approach will include use of Computational Fluid Dynamics (CFD) to predict 2-Phase flow for simplified and representative coolant jacket geometries. This CFD work will assist in getting an understanding of the physics of evaporative cooling, that will in turn assist in the development of robust control strategies to handle what is considered to be a very effective but potentially unstable heat transfer mechanism. A pilot control system will be built allowing the effectiveness of robust control in the presence of vibration and agitation to be experimentally assessed and verified. This 3-year project will be of direct benefit to the academic community since it should generate new fundamental knowledge of evaporative cooling, of particular interest to IC engine research, as existing engine cooling systems are nearing their thermal limits because they exploit forced-convection-based heat transfer involving a water/glycol mixture passing through a coolant jacket. This limit in turn, restricts the performance of both (CI) compression ignition (diesel) engines, and spark ignition (SI) gasoline engines, particularly with engine downsizing, where the intended application could be for conventional or parallel hybrid vehicles, or as compact, high power-weight-ratio range extender engines for Extended Range Electric Vehicles. Evaporative cooling is of considerable interest to automotive vehicle manufacturers and suppliers, because many see the great potential of evaporative cooling over conventional convective systems, to achieve improved IC engine fuel economy and reduced CO2 emissions.

This Evaporative Cooling project will potentially lead to very significant impact in five areas: i) the environment, ii) vehicle user economy, comfort, and safety, iii) improvements in automotive technology, iv) opportunities for manufacturing industries, and v) an expansion of fundamental academic work on extending the thermal limits of internal combustion engines. Apart from the proposed follow-on work to this project, this initiative is expected to motivate research into other areas of importance which are believed to be limiting the thermal capability of internal combustion engines, such as the current coolant medium of water/glycol, albeit its excellence and predominance for the last 40 years. If successful there will be clear impact on academic research, automotive technology, and on the automotive industry, made immediately possible via project partners Ford, Ricardo, and Denso.

The impact on the academic community will include advances in IC engine cooling control and thermal management, heat transfer, and better predictive capability in 2-phase flow.

The impact on automotive technology will be a reduction in automotive CO2 emissions and fuel consumption, also the benefits of faster warm-up, interior heating, and demist, and the associated improvements resulting from better coolant system components for evaporative cooling, such as a smart coolant pump, coolant level sensors, and condenser systems.

The impact on the automotive industry as a whole will be the more powerful approach of evaporative cooling, which if successful, could impact on the design and development of future IC engines globally.