Design and Simulation of Two Stroke Engines

Design and Simulation of Two-Stroke Engines
GPB engine simulation model (continued)
wave reflections at end of pipe (after time stop)
cylinder, atmosphere or plenum, 155-156
discussion, 154-155
"hand," determination of, 154-155
restricted pipe, 155
wave transmission (during time increment dt),
147
Harland & Wolff
cathedral engine (diesel), 3, 5
Heat losses
See Heat transfer
Heat release
compression-ignition engines
combustion chamber geometry, 316-317
direct-ignition (DI) engine, 314-316
fast fuel vs. fast air approach, 314
heat loss by fuel vaporization, 308-309
indirect-injection (IDI) engine, 316-318
Woschni heat transfer equation, 305
frictional (in pressure wave propagation), 82-83
SI engines
combustion chamber geometry, 289, 290
heat loss by fuel vaporization, 308
heat release/heat loss calculations, 291-293
incremental heat loss (where QR is zero), 292
incremental heat release (First-Law expression
for), 291, 293
incremental heat release (Rassweiler and
Winthrow expression for), 293
from loop-scavenged QUB LS400 SI engine,
294, 295
Nusselt number, 305-306, 376
polytropic exponents, determination of, 292,
293
prediction from cylinder pressure diagram,
289-294
Reynolds number, 306
in stratified charging/combustion, 468
thermodynamic equilibrium analysis, 291-293
total heat released, 31, 309-310
see also Combustion processes; Heat transfer
Heat transfer
along duct during time step (GPB model)
introduction, 156
604
First Law of Thermodynamics, application of,
156-158, 160
gas dynamic parameters, values of (for four
cases), 158-159
"hand" of the flow, 160
mass/energy transport diagram (mesh J, four
cases), 156-157
mesh J, energy flow diagram for, 156-157
new reference conditions, determination of,
161-162
purity in mesh space J, 161
system state, change of, 160
in cylinders and plenums during time step (GPB
model)
introduction, 162
boundary conditions, application of, 163-164
First Law of Thermodynamics, application of,
163-165
heat transfer coefficient, determination of
(discussion), 164
heat transfer from/to plenum, expression for,
164
new gas properties, purity, 166
new reference conditions (for next time step),
166
open cycle flow through cylinder (thermodynamic
diagram), 163
sign conventions, importance of, 163
system state, change of, 164
system temperature, solution for, 165
heat losses in GPB engine simulation model,
151
heat transfer analysis (Annand model)
closed cycle model (general), 305-307
crankcase analysis, 375-378
heat transfer coefficients, 307-308
racing motorcycle engine, 397-399
Nusselt number in
defined, 84-85
in convection heat transfer analysis, 84-85
in crankcase heat transfer analysis, 376
in open cycle flow through a cylinder
First Law of Thermodynamics, application of,
163-164
during pressure wave propagation, 84-85
Reynolds number in
in convective heat transfer analysis, 84-85
I