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

2. 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
Turbulent Jet Igniter
Fuel and Air Inlet /
Exhaust Gas Outlet
Hydraulic Reservoir
Pneumatic Piston assembly
Hydraulic Piston
RCM Optical Head
Combustion
Cylinder Piston
High Speed Camera
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= bar (optical) and up to 50 bar (metal)
Temperature= K

3. RCM Direct Test Chamber (DTC) Charge Preparation
Gas Chromatography/Mass Spectrometry (GC/MS)
First stage ignition delay due to low temperature heat release
Overall ignition delay
End of RCM compression stroke
Pressure increase due to RCM compression S
+ Dt for
evaporation
Samples drawn through septum with
a syringe and analyzed in GC/MS
JP-8 sampled at t = 2 min after injection
Application of a Novel Charge Preparation Approach to Testing Autoignition Characteristics of JP-8 and Camelina Hydroprocessed Renewable Jet Fuel in a Rapid Compression Machine, Combustion and Flame, (9):
We cool the body of the injector
emphasize non-volatile fuel testing
- pulse width is tuned to get us integer number of pulse
Compression and ignition of fuel
Introduction of oxidizer/diluent T0, p0
Metered injection of test fuel
Evaporation of fuel inside the chamber (~2 min)
(4)
(1)
(2)
(3)
Fuel Injector 3

4. 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
Turbulent Jet Ignition
Spark Ignition
1.13 ms
1.25 ms
1.38 ms
1.63 ms
2.00 ms
2.25 ms
4.38 ms
10.00 ms

5. Pre-chamber visualization
No Auxiliary Fueling
PW=1.0 ms
Auxiliary fuel injection 1ms pulse
No auxiliary fuel injection

6. RANS Modeling of the TJI Process in the RCM

7. Plans for Future Work RCM Schlieren Imaging
RCM Schlieren Head
Spray imaging in RCM
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
Initial Converge Modeling of Large Bore Truck Engine
Preliminary CVCC Design