How to create orifice plate in pipe flow problem


void defineCylinderGeometry( MultiBlockLattice2D<T,DESCRIPTOR>& lattice,
IncomprFlowParam const& parameters )
const plint nx = parameters.getNx();
const plint ny = parameters.getNy();

plint cx      = nx/2;
plint cy      = ny/2;
plint cz      = ny/2;
plint radius  = cz;

createCylinder(lattice, cx, cy, radius);


this create a circular ball shape geometry in center of pipe of length nx and diameter ny.
the radius of the ball is half of pipe diameter so the passage of pipe is completely blocked.
I have done simulation by shifting this ball shape geometry so that passage in 25% open, 50% open and 75% open.

But now instead of this if I want to have a plate or orifice plate in pipe what I should do, I am not able to create geometry for that. I have tried to create plate.h and plate.hh but still error is coming.

can anyone help to create a orifice plate in pipe flow problem.