PSI - Issue 35

Gaston Haidak et al. / Procedia Structural Integrity 35 (2022) 124–131 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

126

3

Fig. 1. (a) Slipper; (b) Swashplate.

The boundary conditions used are indicated in Fig. 1. The materials used for both slipper and swashplate are Leaded Commercial Bronze and Gray Cast Iron (Sn), respectively. The thermal boundary conditions illustrated in Fig. 1 are used to calculate the thermal stress from the thermal strain due to the loading. We used two different boundary conditions, Neuman Boundary, a natural boundary to specify a wall heat flux, and Mixt Boundary, which specifies a wall heat flux with temperature variation on the surface. The resulting non-uniform temperature distribution causes a thermal expansion of the slipper and swashplate. Thermal stress is calculated from the thermal strain, and this load vector is applied to the solid bodies. The lubricant used in this study is a viscous liquid, the characteristics of which are given in Table 2. The fluid thus described is used in two different aspects: for hydrodynamic simulation between slipper and swashplate and experimental testing. Table 1 presents the geometrical characteristics of the slipper.

Table 1. The geometric characteristics of the machine. Parameters Values

Parameters

Values

Outer diameter slipper [mm] Inner diameter slipper [mm]

25 15

Diameter orifice slipper [mm] Length orifice slipper [mm]

2.5

3.48

Table 2. Characteristics of fluid. Parameters

Values 1.5e-13 0.9000 9.6310 2.1025 3.7873

Parameters

values 0.073

Kinematic viscosity P coefficient Pc1[-] Kinematic viscosity weighting factor w [-] Kinematic viscosity T coefficient Tc1[-] Kinematic viscosity P coefficient Pc2 [-] Kinematic viscosity T coefficient Tc2 [-]

Dynamic oil viscosity [Pa.s]

Density oil at reference point [kg/m3] Heat capacitance [J/kg.K] Volumetric thermal expansion coefficient [1/K] Thermal conductivity of oil [W/m.K]

1048

05.76e-4

0.037 2000

The methodology used for the simulation part can be described in two parts. The first is devoted to the deformation of solid structures (slipper and swashplate), whose type of mesh used is the four-node linear tetrahedron. The summation of the weighted residual approximation over all the elements leads to a global solution approximation. Thus, the general governing elasticity equation (Eq. 1) commonly used, detailed by (Schenk and Ivantysynova, 2015), is used for the thermo-elastic deformation. The solid domain is discretised into many individual finite elements. Similarly, the temperature is assumed to be a weighted linear combination of the four nodal temperatures for the thermal conductivity analysis. ∇ + = 0 (1)