spray injection

mmacrb

hi i am modelling spray injection in 3D.i am using cone injection.i am having problem with spray pattren.i was using cylindrical mesh and fuel was injecting along the axis of the cylinder.the spray pattren was good like a hallow cone. but when i inject in some place other than axis of the cylinder. the whole spray pattren is disturbed. i have also tested spray in square mesh.here if i am injecting at the meeting point of four cells the spray divided into four streams. if i inject in the middle of the cell it donot make hallow cone. it goes stright.

i want hallow cone spray at half angle of 30°.what should i do so that i dont have above problem of changing spray parren with change of point of injection