Numerical simulations of decay of turbulence generated by fan in a constant volume combustion chamber
Standing
Graduate (Masters)
Type of Proposal
Oral Presentation
Faculty
Faculty of Engineering
Faculty Sponsor
Jeff Defoe, Ming Zheng
Proposal
Internal combustion engines involve complex movements of the air-fuel mixture inside the cylinders (due to air intake and piston movement) which have important implications for ignition from a spark plug and flame front propagation. In real engines, the combustion process happens so quickly that the piston doesn’t move significantly from the time ignition occurs until the time the combustion is complete. Thus the volume of the gas during the combustion process is approximately constant. In a lab setting it is therefore possible to model this process using a constant-volume combustion chamber. Such chambers are commonly used to obtain detailed measurements during combustion. To emulate the air-fuel mixture movement, a fan is installed in a constant-volume combustion chamber to generate turbulence. The fan is then turned off and combustion is initiated. The aim of the experiments is to assess different spark plug designs. However, it is not possible to know exactly how much turbulence (and with what characteristics) is generated by the fan at a given rotational speed, nor can the precise rate at which the turbulence decays be known a priori. This makes controlling experiments to match given real-world engine conditions challenging. The work discussed in this presentation provides a solution: use a detailed computer model of the air-fuel mixture inside the constant-volume combustion chamber to determine how the fan speed and amount of time from fan shut-down affect the turbulence characteristics. To ensure the simulations of the fluid accurately represent reality, high-fidelity simulations are employed. This work will enable experimentalists using the chamber to know precisely when to ignite the air-fuel mixture if conditions are intended to match those of a real-world engine for which data is available.
Location
Windsor, ON
Grand Challenges
Sustainable Industry
Numerical simulations of decay of turbulence generated by fan in a constant volume combustion chamber
Windsor, ON
Internal combustion engines involve complex movements of the air-fuel mixture inside the cylinders (due to air intake and piston movement) which have important implications for ignition from a spark plug and flame front propagation. In real engines, the combustion process happens so quickly that the piston doesn’t move significantly from the time ignition occurs until the time the combustion is complete. Thus the volume of the gas during the combustion process is approximately constant. In a lab setting it is therefore possible to model this process using a constant-volume combustion chamber. Such chambers are commonly used to obtain detailed measurements during combustion. To emulate the air-fuel mixture movement, a fan is installed in a constant-volume combustion chamber to generate turbulence. The fan is then turned off and combustion is initiated. The aim of the experiments is to assess different spark plug designs. However, it is not possible to know exactly how much turbulence (and with what characteristics) is generated by the fan at a given rotational speed, nor can the precise rate at which the turbulence decays be known a priori. This makes controlling experiments to match given real-world engine conditions challenging. The work discussed in this presentation provides a solution: use a detailed computer model of the air-fuel mixture inside the constant-volume combustion chamber to determine how the fan speed and amount of time from fan shut-down affect the turbulence characteristics. To ensure the simulations of the fluid accurately represent reality, high-fidelity simulations are employed. This work will enable experimentalists using the chamber to know precisely when to ignite the air-fuel mixture if conditions are intended to match those of a real-world engine for which data is available.