Design and Simulation of Two Stroke Engines

Design and Simulation of Two-Stroke Engines
Various functions of the ratio of specific heats, G5, G7, etc., which are useful as shorthand
notation in many gas-dynamic equations in this theoretical area, are given below. The logic
of the notation for G is that the value of G5 for air is 5, G7 for air is 7, etc.
°3 _ , for air where y = 1.4 then G3 = 3
y - 1 '
r - 3 ~V
u 4 ~ . for air where y = 1.4 then G4 = 4
y - 1 '
r . _2_
°5 ~ - for air where y = 1.4 then G5 = 5
y -1 ' J
r -111
u 6 — i for air where y = 1.4 then G6 = 6
y 1
r - 2 V
^7 ~ , for air where y = 1.4 then G7 = 7
y-1 ' '
r - V" 1 1
°17 _ for air where y = 1.4 then G17 = —
^ 7
y
^35 = _ for air where y= 1.4 then G35 = 3.5
y+ 1 6
^67 ~ ~ for air where y = 1.4 then G67 = —
zy j
This useful notation simplifies analysis in gas dynamics, particularly as it should be noted
that the equations are additive or subtractive by numbers, thus:
r -r 1- 2 1 2-y+l 1-y
G4 = G5 - 1 = - 1 = — = -
y-i y-i y-i
or G7 = G5 + 2 or G3 = G5 - 2 or G6 = G3 + 3.
However, it should be noted in applications of such functions that they are generally
neither additive nor operable, thus:
G7 * G4 + G3 and G3 * —^
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