Realization of the Atkinson-Miller cycle in spark-ignition engine by means of the fully variable inlet valve control system

Abstract The theoretical analysis of the charge exchange process in a spark ignition engine has been presented. This process has significant impact on the effectiveness of engine operation because it is related to the necessity of overcoming the flow resistance, followed by the necessity of doing a work, so-called the charge exchange work. The flow resistance caused by the throttling valve is especially high during the part load operation. The open Atkinson-Miller cycle has been assumed as a model of processes taking place in the engine. Using fully variable inlet valve timing the A-M cycle can be realized according to two systems: system with late inlet valve closing and system with early inlet valve closing. The systems have been analysed individually and comparatively with the open Seiliger-Sabathe cycle which is a theoretical cycle for the classical throttle governing of the engine load. Benefits resulting from application of the systems with independent inlet valve control have been assessed on the basis of the selected parameters: fuel dose, cycle work, charge exchange work and a cycle efficiency. The use of the analysed systems to governing of the SI engine load will enable to eliminate a throttling valve from the system inlet and reduce the charge exchange work, especially within the range of part load operation.

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Improving the effective efficiency of a spark ignition engine through the use of a fully independent valve control system

Combustion Engines ◽

10.19206/ce-141541 ◽

2021 ◽

Author(s):

Zbigniew Żmudka ◽

Stefan Postrzednik

Keyword(s):

Charge Exchange ◽

Spark Ignition Engine ◽

Theoretical Research ◽

Si Engine ◽

Load Range ◽

Engine Operation ◽

Engine Load ◽

Effective Work ◽

Partial Load ◽

Valve Control

The article presents theoretical research of the proposed system of fully independent valve control (FIVC) of the SI engine. The analysis included controlling the movement of the intake valves, which results in adjusting the mass of the fresh charge to the current engine load, as well as the movement of the exhaust valves, where the main aim is to keep the rest of the exhaust gas in the cylinder, i.e. implementation of internal EGR. The open theoretical Seiliger-Sabathe cycle with the classic throttle regulation of load is the reference cycle for assessment of benefits and study of the effectiveness of obtaining work as a result of application of the FIVC system. A comparative analysis of the effectiveness of application of the proposed system was carried out based on the selected quantities: fuel dose, cycle work, relative work of charge exchange and cycle efficiency. The use of the FIVC to regulate the SI engine load makes it possible to eliminate the throttle and thus reduce the charge exchange work, especially in the partial load range. And this then leads to an increase in internal and effective work, which in turn results in an increase in the effective energy efficiency of an engine operation.

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A Multiple-Zone Cycle Simulation for Spark-Ignition Engines: Thermodynamic Details

Volume 2: Large-Bore Engines, Fuel Effects, Homogeneous Charge Compression Ignition, Engine Performance and Simulation ◽

10.1115/2001-ice-412 ◽

2001 ◽

Cited By ~ 5

Author(s):

Jerald A. Caton

Keyword(s):

Combustion Process ◽

Load Condition ◽

Engine Performance ◽

Thermodynamic Cycle ◽

Spark Ignition ◽

Spark Ignition Engine ◽

Engine Operation ◽

Part Load ◽

Cycle Simulation ◽

The Individual

Abstract A thermodynamic cycle simulation was developed for a spark-ignition engine which included the use of multiple zones for the combustion process. This simulation was used to complete analyses for a commercial, spark-ignition V-8 engine operating at a part load condition. Specifically, the engine possessed a compression ratio of 8.1:1, and had a bore and stroke of 101.6 and 88.4 mm, respectively. A part load operating condition at 1400 rpm with an equivalence ratio of 1.0 was examined. Results were obtained for overall engine performance, for detailed in-cylinder events, and for the thermodynamics of the individual processes. In particular, the characteristics of the engine operation with respect to the combustion process were examined. Implications of the multiple zones formulation for the combustion process are described.

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Throttleless control of SI engine load by fully flexible inlet valve actuation system

Combustion Engines ◽

10.19206/ce-116488 ◽

2016 ◽

Vol 164 (1) ◽

pp. 44-48

Author(s):

Zbigniew ŻMUDKA ◽

Stefan POSTRZEDNIK ◽

Grzegorz PRZYBYŁA

Keyword(s):

Charge Exchange ◽

Spark Ignition Engine ◽

Inlet Valve ◽

Inlet System ◽

Engine Load ◽

Actuation System ◽

Partial Load ◽

Effective Efficiency ◽

Cycle Efficiency ◽

Valve Actuation

A system with independent, early inlet valve closure (EIVC) has been analysed. The open, theoretical cycle has been assumed as a model of processes proceeding in the engine with variable inlet valve actuation. The system has been analysed individually and comparatively with open Seiliger-Sabathe cycle which is theoretical cycle for the classic throttle governing of engine load. The influence of EIVC on fuel economy, cycle work, relative charge exchange work and cycle efficiency has been theoretically investigated. The use of the analysed system to governing of an engine load will enable to eliminate a throttling valve from inlet system and reduce the charge exchange work, especially within the range of partial load. The decrease of the charge exchange work leads to an increase of the internal and effective works, which results in an increase of the effective efficiency of the spark ignition engine.

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Flow resistance in the engine inlet-exhaust system as affected by the engine parameters

Combustion Engines ◽

10.19206/ce-117218 ◽

2009 ◽

Vol 136 (1) ◽

pp. 31-40

Author(s):

Zbigniew ŻMUDKA ◽

Stefan POSTRZEDNIK

Keyword(s):

Pressure Drop ◽

Flow Resistance ◽

Exhaust System ◽

Spark Ignition ◽

Spark Ignition Engine ◽

Test Results ◽

Flow Conditions ◽

Inlet System ◽

Engine Operation ◽

Fresh Charge

The paper presents theoretical and experimanetal research into the process of charge exchange in a spark ignition engine (the process of cylinder filling and discharging). A significant role in the inlet system plays the resistance of the flow of a fresh charge through the throttle, particularly when its partially opened. In classic spark ignition engine solutions this flow resistance is a part of the engine load imposition. The problem has been illustrated by the theoretical and experimental test results of the influence of the pressure drop Δpd on the side of the fresh charge flow and the pressure drop Δpw in the exhaust system on the engine operation. Relations have been determined between the engine operating parameters and the flow conditions of the charge/exhaust gases.

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