ABSTRACTA new derivation considering the non-linear terms has been proposed to calculate stiffness and damping coefficients for short hydrodynamic journal bearings lubricated with pseudo-plastic fluids. The proposed method has relaxed the constraint of small perturbation method applicable to only small values of non-Newtonian factor α. An analytical solution is also given. The non-linear Reynolds equation is solved with a more reasonable boundary condition ∂p*/∂z* = 0 at the location of z*=0 while the analytical pressure distribution is obtained by seven-point Gauss-Legendre integral formula. When the non-dimensional non-Newtonian factor α is small, the stiffness and damping coefficients of computed by the proposed method can agree well with those from small perturbation method, which could verify the proposed derivation. As for large non-dimensional non-Newtonian factor α, the stiffness coefficients
$K_{XX}^*$
,
$K_{XY}^*$
and
$K_{YX}^*$
as well as the damping coefficients
$C_{XX}^*$
,
$C_{XY}^*$
and
$C_{YX}^*$
decrease with the increasing of non-dimensional non-Newtonian factor α. The significance of the derivation is that it can relax the constraint of small α and simplify the computation process.
INVERSION OF ELECTRICAL AND GEOMETRICAL PARAMETERS OF A STRATIFIED MEDIUM FROM DATA DERIVED FROM THE SMALL PERTURBATION METHOD AND THE SMALL SLOPE APPROXIMATION
