Finite-element analysis of a constant-force solenoid for fluid flow control

A model for constant-force solenoids based on the finite-element method is presented. The total force exerted by the solenoid is calculated and compared with test results. The force calculation algorithm is also used to determine the force distribution pattern around the plunger surface, and to provide a detailed analysis of the solenoid structure. The model was successfully implemented to improve a solenoid design. The finite-element package is shown to be a powerful design tool, capable of accurate performance prediction. The analysis process shows the importance of the truncated-cone shape of the plunger, of balancing the forces produced by the tapered and flat portions of the plunger surface, and of matching the respective positions of the plunger and of the facing pole. >