Modelling the Dissipative Effect of Seal Air Hole Spacing and Size on Door Closing Effort

Door weather strip seals are designed with ventilation holes spaced at regular intervals along the seal system to expedite the flow of air from the seal system during the door closing process. The flow of air through the ventilation holes represents a nonlinear damping mechanism which, depending upon hole size and spacing, can significantly contribute to door closing effort.

In this study we develop one- and two- dimensional versions of a nonlinear damping model for seal compression load deflection (CLD) behavior which incorporate the effects of seal damping response due to air flow through the ventilation holes. The air flow/damping models are developed from first physical principles by application of the mass and momentum balance equations to a control volume of entrapped air between consecutive air ventilation holes in the seal system. Both model formulations indicate that the damping component of seal force per unit length generated during seal compression is directly proportional to , where L and D represent, respectively, the spacing distance and diameter of the air ventilation holes. Numerical predictions for the damping force at a section in a production vehicle door seal system during closing are made using the two models and results compared.