Assignment 5

Fig.5.Schematic diagram of the hydraulic system: 1 – tank; 2 – pump; 3 – non-return valve; 4 – filter; 5 – relief valve

Volumetric pump (Fig.5.) supplies liquid to two hydraulic cylinders (flap extension and retraction), loaded by F₁ and F₂ forces. Pistons velocity is V_p. The gage pressure in the tank is P_m. The aircraft flight altitude is H.

Determine:

1. Pressure in the cylinders drain, if the summary resistance coefficient at sector CK is φ.

2. Throttles diameter, if the chokes resistance coefficients are φ₁, φ₂, and pressure at point B isP_b.

3. Pump pressure head.

4. The absolute pressure at the pump entrance.

Solution technique:

1. Determine the liquid consumption in the pipelines at EC and CK sectors.

2. Determine the liquid flow velocity in the pipelines at EC sectors, Re-number, λ and Σh₀.

3. Find liquid flow velocity in the pipelines at CK sector.

4. Calculate the pressure head in the cylinder drain.

5. Determine pump delivery and liquid flow rate through throttles, using given V_n and D data.

6. Calculate the throttles diameter, using given pressure P_b, values of coefficients φ₁ and φ₂ values and liquid flow rate.

7. Determine the liquid flow velocity in the pipe, Re-number, λ, pressure losses Σh in the AB sector.

8. Determine the pressure head, produced by the pump.

9. Calculate absolute pressure value at the pump entrance.

Table 5