Design and Simulation of Two Stroke Engines

Design and Simulation of Two-Stroke Engines
Particle velocity, determination of (continued)
in pressure wave reflection (in pipes) (continued)
outflow from a cylinder, 132-133
at restrictions between differing pipe areas,
112-113
in pressure wave superposition (in pipes)
oppositely moving waves, 71
supersonic particle velocity (oppositely moving
waves), 74-77
in unsteady gas flow
Bannister derivation of, 197-200
see also Gas flow (related terms)
Performance measurement
brake mean effective pressure
AFR, effect of (low-emissions engine), 487
AFR, effect of (QUB 400 engine), 472,474,
476
defined, 37
exhaust silencing, effect of (chainsaw engine),
574, 576
influence of engine type on, 45
intake silencing, effect of (chainsaw engine),
571
and power output, 37
QUB 270 cross-scavenged airhead-stratified
engine, 510-511
QUB stratified charging engine, 499, 500
radiused porting, effect of (chainsaw engine),
579
scavenging type, influence of, 484-486
of typical two-stroke engines, 43
various fueling, effect of (QUB 500rv engine,
full load), 523
various fueling, effect of (QUB 500rv engine,
light load), 529
vs. rpm (chainsaw engine simulation), 380,
381
see also mean effective pressure (below)
brake power output
See power output (below)
brake specific fuel consumption
See under Fuel consumption/fuel economy
brake thermal efficiency (defined), 37
brake torque (defined), 36
dynamometer testing
introduction and discussion, 35-36
dynamometer test stand (functional flow diagram),
36, 37
608
performance parameters, 36-38
principles of, 36
friction mean effective pressure
determination of (in engine testing), 38
indicated mean effective pressure
defined, 38
mean effective pressure (mep)
concept of (discussion), 34
piston speed
and brake power output, 44-45
power output
and brake mean effective pressure, 37
brake power output (defined), 36
brake power output vs. piston speed/swept
volume, 44-45
and brake specific fuel consumption, 37
of chainsaws (typical), 45
engine type, influence of, 45-46
four-stroke engine (GPB model), 169
indicated (defined), 34-35
silencer design for high power output (motorcycle
engines), 581
two-stroke engine (GPB model), 169
two-stroke engines, potential power output of,
43
vs. rpm (chainsaw engine simulation), 380,
381
pumping mean effective pressure
determination of (in engine testing), 38
swept volume
and brake power output, 44-45
Petroil lubrication, 12-13, 14, 470
see also Lubrication
Piaggio stratified charging engine
introduction and functional description,
500-501
benefits and advantages of, 504
CO emissions, 502-503
fuel consumption levels, 501-503
hydrocarbon emissions, 503
Piston speed
and brake power output, 44-45
and speed of rotation, 44-45
Pistons
cross-scavenged deflector (typical), 10, 11
deflector designs. See Port design, scavenging
for loop-scavenged engine, 10
piston motion, importance of (in scavenging
flow), 223-224
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