Joseph Scalzo

Exploring the Advantages of Atkinson Effects in Variable Compression Ratio Turbo GDI Engines

The Atkinson cycle engine is basically an engine permitting the strokes to be different lengths for improved light loads fuel economies. Variable compression ratio is the technology to adjust internal combustion engine cylinder compression ratio to increase fuel efficiency while under varying loads. The paper presents a new design of a variable compression ratio engine that also permits an expansion ratio that may differ from the compression ratio therefore generating an Atkinson cycle effect. The stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. The variable ratio of maximum to minimum in-cylinder volumes also improves the full load power output of the engine. Results of performance simulations are proposed for a gasoline engine 2 Litres, in-line four, turbocharged and direct injection showings significant fuel savings during light and medium loads operation as well as improvement of full load output and fuel efficiency.

A Novel Wankel Engine Featuring Jet Ignition and Port or Direct Injection for Faster and More Complete Combustion Especially Designed for Gaseous Fuels

Hydrogen Internal Combustion Engine (ICE) vehicles using a traditional ICE that has been modified to use hydrogen fuel are an important mid-term technology on the path to the hydrogen economy. Hydrogen-powered ICEs that can run on pure hydrogen or a blend of hydrogen and compressed natural gas (CNG) are a way of addressing the widespread lack of hydrogen fuelling infrastructure in the near term. Hydrogen-powered ICEs have operating advantages as all weather conditions performances, no warm-up, no cold-start issues and being more fuel efficient than conventional spark-ignition engines. The Wankel engine is one of the best ICE to be converted to run hydrogen. The paper presents some details of an initial investigation of the CAD and CAE modeling of a novel design where two jet ignition devices per rotor are replacing the traditional two spark plugs for a faster and more complete combustion. The CAE model (by using the GT-SUITE software [7]) is developed first to describe the wide open throttle operation of the baseline two rotor twin spark plugs per rotor, gasoline port fuel injected Mazda Renexis high power engine. The model is then converted to describe the operation of gasoline or hydrogen fuelled versions with two jet ignition devices replacing the spark plugs.

Novel Crankshaft Mechanism and Regenerative Braking System to Improve the Fuel Economy of Passenger Cars

Improvements of vehicle fuel economy may be achieved by the introduction of advanced internal combustion engines (ICE) improving the fuel conversion efficiency of the engine and of advanced power trains (PWT) reducing the amount of fuel energy needed to power the vehicle. The paper presents a novel design of a variable compression ratio advanced spark ignition engine that also permits an expansion ratio that may differ from the compression ratio hence generating an Atkinson cycle effect. The stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. The variable ratio of maximum to minimum in-cylinder volumes also improves the full load torque output of the engine. The paper also presents an evolved mechanical kinetic energy recovery system delivering better round trip efficiencies with a design tailored to store a smaller quantity of energy over a reduced time frame with a non-driveline configuration. Simulations show an improvement of full load torque output and fuel conversion efficiency. Brake specific fuel consumption maps are computed for a gasoline engine 2 litres, in-line four, turbocharged and directly fuel injected showings significant fuel savings during light and medium loads operation. Results of vehicle driving cycle simulations are presented for a full size car equipped with the 2 L turbo GDI engine and a compact car with a downsized 1 L turbo GDI engine. These results show dramatic improvements of fuel economies for similar to Diesel fuel energy usage and CO2 production. The turbo GDI engines with the alternative crank trains offer better than hybrids fuel economies if the vehicles are also equipped with the novel mechanical kinetic energy recovery system (KERS) recovering the braking energy to reduce the thermal energy supply in the following acceleration of a driving cycle.

Exploring the Advantages of Variable Compression Ratio in Internal Combustion Engines by Using Engine Performance Simulations

Variable compression ratio is the technology to adjust internal combustion engine cylinder compression ratio to increase fuel efficiency while under varying loads. The paper presents a new design of a variable compression ratio engine that allows for the volume above the piston at Top Dead Centre (TDC) to be changed. A modeling study is then performed using the WAVE engine performance simulation code for a naturally aspirated gasoline V8 engine. The modeling study shows significant improvements of fuel economy over the full range of loads and especially during light loads operation as well as an improvement of top power and torque outputs. Adjusting the Compression Ratio CR from the low speed wide open throttle knock limited value of CR=10:1 to a variable CR=10:1 to 15:1 for better or about same margin to knock over the full range of engine speeds and loads, maximum torque, power and brake engine thermal efficiency are increased by 5%, 12.5% and 4.5% respectively, while operating at 1 bar Brake Mean Effective Pressure (BMEP) and 2 bar BMEP the brake thermal engine efficiency is up to 10% better.

A Novel Mechanism for Piston Deactivation Improving the Part Load Performances of Multi Cylinder Engines

Cylinder deactivation has been proposed so far for improved part load operation of large gasoline engines. In all this application, the cylinder deactivation has been achieved keeping the intake and exhaust valves closed for a particular cylinder, with pistons still following their strokes. The paper presents a new mechanism between the piston and the crankshaft to enable selective deactivation of pistons, therefore decoupling the motion of the piston from the rotation of the crankshaft. The reduced friction mean effective pressure of the new technology enables the use of piston deactivation in large engines not necessarily throttle controlled but also controlled by quantity of fuel injected. Results of performance simulations are proposed for V8 gasoline and Diesel engines producing significant savings during light operation, larger for the gasoline but still substantial for the Diesel.

Alternative Crankshaft Mechanisms and Kinetic Energy Recovery Systems for Improved Fuel Economy of Light Duty Vehicles

The introduction of advanced internal combustion engine mechanisms and powertrains may improve the fuel conversion efficiency of an engine and thus reduce the amount of energy needed to power the vehicle. The paper presents a novel design of a variable compression ratio advanced spark ignition engine that also permits an expansion ratio that may differ from the induction stroke therefore generating an Atkinson cycle effect. The stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. The variable ratio of maximum to minimum in-cylinder volumes also improves the full load power output of the engine. Results of vehicle driving cycle simulations of a light duty gasoline vehicle with the advanced engine show dramatic improvements of fuel economy. The novel gasoline vehicle has close to diesel fuel energy usage and CO2 production while retaining the after treatment advantages of the stoichiometric operation with spark ignition. Coupled to advanced powertrains using mechanical kinetic energy recovery systems to recover the braking energy thus reducing the thermal energy supply in the following acceleration phase, these engines may offer even better than current hybrid electric vehicles fuel economy (comparison of compact size passenger cars with a turbo direct injection diesel and a mechanical kinetic energy recovery system and a gasoline hybrid electric vehicle published in a previous paper). The results of the paper are based on modelling techniques. These results need to be confirmed by experiments.

A Naturally Aspirated Four Stroke Racing Engine with One Intake and One Exhaust Horizontal Rotary Valve per Cylinder and Central Direct Injection and Ignition by Spark or Jet

The paper discusses the benefits of a four stroke engine having one intake and one exhaust rotary valve. The rotary valve has a speed of rotation half the crankshaft and defines an open passage that may permit up to extremely sharp opening or closing and very large gas exchange areas. The dual rotary valve design is applied to a racing engine naturally aspirated V-four engine of 1000cc displacement, gasoline fuelled with central direct injection and spark ignition. The engine is then modeled by using a 1D engine & gas dynamics simulation software package to assess the potentials of the solution. The improved design produces much larger power densities than the version of the engines with traditional poppet valves revving at higher speeds, with reduced frictional losses, and with larger gas exchange areas while also improving the fuel conversion efficiency thanks to the sharpness of opening or closing events. The novelty in the proposed dual rotary valve system is the combustion chamber of good shape and high compression ratio with central direct injector and spark plug coupled to the large gas exchange areas of the rotary valve system. Finally, jet-ignition is shown as a valuable tool to improve the rate of combustion also in stoichiometric and near stoichiometric racing engines applications with benefits in terms of fuel conversion efficiency and combustion stability.

Novel Crankshaft Mechanism and Regenerative Braking System to Improve the Fuel Economy of Light Duty Vehicles and Passenger Cars

Improvements of vehicle fuel economy may be achieved by the introduction of advanced internal combustion engines (ICE) improving the fuel conversion efficiency of the engine and of advanced power trains (PWT) reducing the amount of fuel energy needed to power the vehicle. The paper presents a novel design of a variable compression ratio advanced spark ignition engine that also permits an expansion ratio that may differ from the compression ratio hence generating an Atkinson cycle effect. The stroke ratio and the ratio of maximum to minimum in-cylinder volumes may change with load and speed to provide the best fuel conversion efficiency. The variable ratio of maximum to minimum in-cylinder volumes also improves the full load torque output of the engine. The paper also presents an evolved mechanical kinetic energy recovery system delivering better round trip efficiencies with a design tailored to store a smaller quantity of energy over a reduced time frame with a non-driveline configuration. Simulations show an improvement of full load torque output and fuel conversion efficiency. Brake specific fuel consumption maps are computed for a gasoline engine 2 liters, in-line four, turbocharged and directly fuel injected showings significant fuel savings during light and medium loads operation. Results of vehicle driving cycle simulations are presented for a full size car equipped with the 2 liters turbo GDI engine and a compact car with a downsized 1 liter turbo GDI engine. These results show dramatic improvements of fuel economies for similar to Diesel fuel energy usage and CO2 production. The turbo GDI engines with the alternative crank trains offer better than hybrids fuel economies if the vehicles are also equipped with the mechanical kinetic energy recovery system (KERS) recovering the braking energy to reduce the thermal energy supply in the following acceleration of a driving cycle.