  We find the Green's functions for the accretion disk with the fixed outer
radius and time-independent viscosity. With the Green's functions, a viscous
evolution of the disk with any initial conditions can be described. Two types
of the inner boundary conditions are considered: the zero stress tensor and the
zero accretion rate. The variable mass inflow at the outer radius can also be
included. The well-known exponential decline of the accretion rate is a part of
the solution with the inner zero stress tensor. The solution with the zero
central accretion rate is applicable to the disks around stars with the
magnetosphere's boundary exceeding the corotation radius. Using the solution,
the viscous evolution of disks in some binary systems can be studied. We apply
the solution with zero inner stress tensor to outbursts of short-period X-ray
transients during the time around the peak. It is found that for the Kramers'
regime of opacity and the initial surface density proportional to the radius,
the rise time to the peak is t_rise ~ 0.15 r_out^2/nu_out and the e-folding
time of the decay is t_exp ~ 0.45 r_out^2/nu_out. Comparison to non-stationary
alpha-disks shows that both models with the same value of viscosity at the
outer radius produce similar behaviour on the viscous time-scale. For six
bursts in X-ray novae, which exhibit fast-rise-exponential-decay (FRED) and are
fitted by the model, we find a way to restrict the turbulent parameter alpha.
