Design and Simulation of Two Stroke Engines

Design and Simulation of Two-Stroke Engines
Turbocharged/supercharged engines (continued)
functional description, basic, 13-14
loop scavenging port design, external (blown
engines)
BLOWN PORTS (computer program),
270-273
designs for (discussion), 269-270
four-cylinder DI diesel, design for, 272-273
typical layout, 270, 271
Roots blower in (fuel-injected engine), 13-14,
15
Turbulence
advantages of (in alternative fuel combustion),
339
Two-stroke engine (general)
advantages of, 5
applications, typical
automobile racing, 2-3
handheld power tools, 1 -2, 3
outboard motors, 2, 4
see also Compression ignition engines
engine geometry, elements of
compression ratio, 22
computer programs used (introduction),
20-21
LOOP ENGINE DRAW (computer program),
23, 24, 25
PISTON POSITION (computer program),
23,24
piston position vs. crankshaft angle, 21,22-23
QUB CROSS ENGINE DRAW, 25-26
swept volume/trapped swept volume, 21
units used, 20
fundamental operation (basic engine)
charge transfer/scavenging, 6, 7-8
exhaust closure (trapping), 6, 8
fuel induction, alternatives for, 7
functional diagram, 6
geometric compression ratio (defined), 8
initial exhaust (blowdown), 6, 7
power stroke/induction, 6-7
short circuiting, 8
trapped compression ratio (defined), 8
trapping point, 8
opinions regarding, 4-5
port timing, elements of
introduction, 18
disc-valved engine, 18, 19, 20
622
piston-ported engine, 18-19
reed-valved engine, 18, 20
timing diagrams, typical, 18
see also specific valves; Combustion processes;
Port design; Scavenging
Valves/valving
introduction to
disc valves, 16, 17
function of, 15-16
poppet valves, 16
port timing characteristics, typical (reed and
disc valves), 18
reed valves, 17
typical configuration (disc valve), 16
typical configuration (reed valve), 16, 19
see also specific valves; Computer modeling;
Port design; Port timing
Velocette motorcycle engine, 490
Vespa motor scooter engine
Batoni performance maps (CO emissions),
476-478
Vibe, I.I.
mass fraction burned analysis (SI engine), 295,
309-310
Vortex formation
in uniflow scavenging, 253
Wallace, F.J.
simulation of engines (using unsteady gas flow),
143
"Water-gas" reaction, 297, 346
see also Combustion processes; Exhaust emissions/exhaust
gas analysis
Wendroff, B.
Lax-Wendroff computation time, 191-192
simulation of engines (using unsteady gas flow),
142
Winthrow, L.
expression for incremental heat release (SI engines),
293
Work
pressure wave propagation (straight pipes)
friction work and heat generated, 83
work done during engine cycle (GPB model),
168-169