MSU Rapid Compression Machine and Turbulent Jet Ignition

MSU Rapid Compression Machine and Turbulent Jet Ignition Testing Dr. Elisa Toulson Assistant Professor Department of Mechanical Engineering, Michigan State University

Rapid Compression Machine A rapid compression machine uses a single mechanical stroke of a piston to compress a charge of fuel and air to an elevated temperature and pressure suitable for combustion High Speed Camera Turbulent Jet Igniter Combustion Cylinder Piston RCM Optical Head 7/29/2016 Fuel and Air Inlet / Exhaust Gas Outlet Hydraulic Piston Hydraulic Reservoir Pneumatic Piston assembly Key Features § Pneumatically driven and hydraulically stopped § Variable compression ratio § Controlled Chamber Wall Temperature § Optical Access for combustion visualization § Effective Compression Time: 7 ms § Compressed Conditions • Pressure= 10 -30 bar (optical) and up to 50 bar (metal) • Temperature= 600 -1000 K 2

RCM Direct Test Chamber (DTC) Charge Preparation Gas Chromatography/Mass Spectrometry (GC/MS) Overall ignition delay Samples drawn through septum with a syringe and analyzed in GC/MS End of RCM compression stroke Pressure increase due to RCM compression First stage ignition delay due to low temperature heat release S + Dt for evaporation S JP-8 sampled at t = 2 min after injection Fuel Injector (1) Introduction of oxidizer/diluent gases @ T 0, p 0 (2) Metered injection of test fuel (3) Evaporation of fuel inside the chamber (~2 min) (4) Compression and ignition of fuel

Turbulent Jet Ignition TJI is a pre-chamber ignition enhancement concept that produces a distributed ignition source through the use of a jet undergoing combustion Advantages • Fast burning rates • Knock mitigation • Facilitates lean combustion and ignition of highly dilute mixtures Spark Ignition Turbulent Jet Ignition 7/29/2016 1. 13 ms 1. 25 ms 1. 38 ms 1. 63 ms 2. 00 ms 2. 25 ms 4. 38 ms 10. 00 ms 4

No Auxiliary Fueling PW=1. 0 ms Prechamber visualization No auxiliary fuel injection Auxiliary fuel injection 1 ms pulse 7/29/2016 5

RANS Modeling of the TJI Process in the RCM 6

Plans for Future Work • RCM Schlieren Imaging • RCM testing and optical imaging of a natural gas TJI system for large bore truck engines • RANS modeling of TJI system in large bore truck engine • Autoignition and spray testing of ethanol gasoline blends in RCM • Construction of Optical Constant Volume Combustion Chamber (CVCC) for laminar flame speed measurements RCM Schlieren Head Initial Converge Modeling of Large Bore Truck Engine Spray imaging in RCM Preliminary CVCC Design 7