Flow diagnostics engine: a new system for piston engine research

Thesis/Dissertation · Sat Jan 01 00:00:00 EST 1983

OSTI ID:6707853

Richman, R M

As an initial step towards obtaining a better understanding of the fluid mechanics and related processes in the internal combustion engine, a unique visualization engine was developed and demonstrated. The Flow Diagnostics Engine (FDE) is a single-cylinder engine with a transparent cylinder made from single-crystal sapphire. In constrast to previous efforts, the FDE has an internal geometry very similar to that of production engines. A computer-controlled valve-actuation system was developed for the FDE. The valve actuators are fast electro-hydraulic devices which, with a minicomputer, provide complete control over the value motion. To visualize the flows in the engine cylinder, a special schlieren system was developed and demonsrated. A conventional schlieren system could not be used, because the curvature of the transparent cylinder wall introduced severe aberrations. In the new system, a holographic optical element was constructed and used to correct the aberrations. To demonstrate the feasibility and usefulness of the FDE system, flows in both conventional and swirl engine geometries were visualized and recorded with high-speed cinematography. The visualization provides qualitative information about the flow and allows observation of: 1) the development and motions of large recirculation zones during the intake event, 2) the appearance of small-scale turbulence and the changes in scale caused by compression and expansion, 3) the expansion of ring crevice gases into the cylinder during the beginning of the exhaust event, and 4) the large-scale motions associated with intake swirl. The FDE system is very versatile and can accommodate a wide variety of engine geometries, operating conditions, and optical diagnostics. Only a few of the many possibilities were explored.

• OSTI ID: 6707853
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
INTERNAL COMBUSTION ENGINES
FLUID MECHANICS
COMPUTERIZED CONTROL SYSTEMS
FEASIBILITY STUDIES
FLUID FLOW
MICROPROCESSORS
PERFORMANCE
COMPUTERS
CONTROL SYSTEMS
ELECTRONIC CIRCUITS
ENGINES
HEAT ENGINES
MECHANICS
MICROELECTRONIC CIRCUITS
330100* - Internal Combustion Engines