The harmful effect on the environment of noxious exhaust gas emissions – HC, CO and NOx – is long-established. Attention is now turning to the greenhouse gas carbon dioxide. Recent national and international responses to climate change are driving the development of more economical vehicles – which produce less CO2 – and therefore more efficient engines. Direct-injection fuel systems are a key component in high-efficiency gasoline engines. Ricardo first developed direct injection gasoline engines in the 1930s, for application in aircraft. Since then, Ricardo are recognised worldwide as one of the key developers of direct injection technology for use in passenger cars. Ricardo have undertaken a large volume of direct injection work, on a research, collaborative and contract basis, and have experience of all of the existing direct injection combustion systems.
Downsizing the Gasoline Engine
Engine downsizing describes the substitution of a naturally-aspirated engine by an engine of smaller swept volume, and the downsized engine is typically turbocharged. The introduction of downsized engines is a key element of a powertrain strategy to meet future requirements for reduced carbon dioxide emissions and fuel consumption. Ricardo have developed a number of alternative concepts for downsized DI gasoline engines, each seeking maximum indicated efficiency by maintaining high compression ratio, dilution and other measures. Each concept has been experimentally investigated using a multi-cylinder turbocharged DI gasoline engines, and the most promising concept – Lean Boost DI (LBDI) – has been further developed with a demonstrator vehicle programme.
Advanced Valvetrains
A clear trend in engine development is the pursuit of greater levels of flexibility. The valvetrain, with its controlling role over engine operation, is a prime candidate for increased flexibility. Variable valve actuation (VVA) – including both mechanical systems and camless engines – reduces the need for compromise when developing engine performance, exhaust emissions and fuel economy. Drawing on years of experience, Ricardo offer a complete system approach to selection, design and development of the valvetrain. A sophisticated range of tools are on offer to ensure that requirements for functionality, durability and cost are met. Ricardo have developed in-house mechanical VVA systems, have an active camless engine research programme, and are conversant with all of advanced valvetrain systems available in the marketplace.
CAI and HCCI Combustion Systems
Recent years have witnessed great interest in a new class of combustion systems usually described as either Homogeneous Charge Compression-Ignition (HCCI) combustion or Controlled Auto-Ignition (CAI) combustion. These combustion systems differ fundamentally from the two conventional modes – spark-ignition and compression-ignition combustion – in that they operate by the auto-ignition of an approximately homogeneous charge. HCCI/CAI engines produce exceptionally low NOx emissions, and have the potential for very good fuel economy. Ricardo have undertaken a substantial internal research programme to investigate gasoline CAI combustion. This programme has demonstrated CAI combustion in both two-stroke and four-stroke engines, and further illuminated CAI engine processes. Techniques used include conventional engine testing and optical engine testing, and the development of Ricardo Software simulation packages to treat gasoline HCCI and CAI combustion.
High-Performance Gasoline Engines
With a racing pedigree stretching back to 1921, Ricardo have a number of long-standing achievements in the worlds of motorsport and high-performance vehicles. Ricardo are able to apply to apply the knowledge gained from this heritage along with ongoing competition experience across the spectrum of high-performance gasoline engines. In a typical high-performance engine project, Ricardo might be tasked with providing an optimised torque curve, variable valve-timing (VVT) strategy, vehicle calibration and durability development. Within constraints such as packaging, production requirements and emissions targets, the maximum output must be achieved, along with an appropriate performance calibration. To find out more please visit our dedicated Motorsport pages.
Major Development Programmes
Major engine development programmes place particular demands on all those involved. Ricardo have a track record of success in delivering major projects on time and with the highest quality. From pre-concept through to production support, Ricardo have experience in all phases of engine development programmes. Flexibility is the key to successful delivery of major projects. In addition to Ricardo project management techniques, we have experience of five major OEM gateway processes. All Ricardo Technical Centres can support extensive project offices. These provide a confidential base for client, supplier and Ricardo engineers to work together. Equally, Ricardo can provide experienced engineers to work at your own site
