Design and Simulation of Two Stroke Engines

Design and Simulation of Two-Stroke Engines
mass flow increments must be equal to satisfy the continuity equation. The difference in the
enthalpy terms can be evaluated as:
to:
hs - h0 = Cp(Ts - T0) = -£-CT, " To) - ^4-
Y-l Y-1
Although the particle velocity in the atmosphere, co, is virtually zero, Eq. 2.8.4 reduces
As the flow is isentropic, from Eq. 2.1.12:
c 2 , + G54 = cs 2 + G5as 2 (2.8.5)
as = aoXs
Substituting Eq. 2.8.6 into Eq. 2.8.5 and now regarding co as zero:
From Eq. 2.2.6:
From Eq. 2.2.1:
c 2 = G5ag(l - Xs 2 )
cs = G5ao(Xi-Xr)
Xs = Xi + Xr-l
Bringing these latter three equations together:
This becomes:
G5(Xi - Xr) 2 = 1 - (X, + Xr - l) 2
(2.8.6)
(2.8.7)
(2.8.8)
(2.8.9)
G6X 2 - (2G4Xi + 2)Xr + (G6X 2 - 2Xj) = 0 (2.8.10)
This is a quadratic equation solution for Xr. Ultimately neglecting the negative sign in the
general solution to a quadratic equation, this yields:
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