## Lecture 3-3: The Fluid Solver (3/3)

The boundaries of the computational domain coincide with
The pressure and velocity control volumes
The pressure and vertical velocity control volumes
The pressure and horizontal velocity control volumes
The velocity control volumes only
None of the above

Ghost points are used to enforce
The normal velocity
The tangent velocity
Both normal and tangent velocity
Specify a given inflow
None of the above

The no-slip boundary conditions for the tangent velocity at a stationary solid wall can be enforced by setting the velocity at a ghost point equal to
The velocity at the first point inside the domain
Zero
The negative of the velocity at the first point inside the domain
The tangent velocity at the ghost point is not used and can be anything
None of the above

The normal velocity at a the edge of the computational domain
Can be specified using ghost points
Is found by interpolating between a ghost point and the first inside point
Is always equal to zero
Is equal to the inflow/outflow velocity
None of the above

The pressure boundary conditions
Can be enforced by using very large density at the ghost points
Can be enforced by putting the pressure at the ghost points equal to the first inside point
Is determined using the mass conservation equation
Can be found by rewriting the pressure equation
All of the above

Continuum theory predicts that the evolution of the density is governed by
A wave equation
A parabolic equation
None of the above

The method described here is
First order in time and space
Second order in time and space
Second order in time and first order in space
First order in time and second order in space
None of the above

For the size of the time step:
There is no limit on the size of the time step
High velocity requires small time step
High viscosity requires small time step
High velocity and high viscosity requires small time step
None of the above

As the drop falls, we expect that the
Density interface remains sharp
The density in the drop to change
The drop to stay spherical
The drop to remain stationary
All of the above

The main reason for the difference between the computed solution and the correct one is
The method is only first order
The density advection is not correct
The viscosities are assumed to be the same
Surface tension is zero
None of the above