BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI - Universitatea ...

162 Constantin Chirita et al.
a) b)
Fig. 1 – Hydraulic charts for lower frequencies and small flow generators.
The mathematical models presented in the following rows are equal satisfied
for both variants.
2. Mathematical Models for the Stationary Regime
For the engine CH which works on the strength F, when a small quantity of
oil V, ideal liquid, incompressible, theoretical we obtain a theoretical movement
of the mass, xT, with the mathematical expression:
(1)
V
xT = .
S
For a real liquid, with the elasticity module E, we obtain a real movement, in
static regime, xP.
⎛ p ⎞
(2) xR = xT
⋅⎜1
− ⎟ .
⎝ E ⎠
(3)
In the relation (2) p is the balance pressure.
F
p = .
S
For V = 8 cm 3 , S = 80 cm 2 , F= 32.000 N, E = 1,5e9 N/m 2 , the results are:
xT= 1 mm, xR= 0,999 mm.