Abstract
Recently there is a growing need for micro water cooling systems with the development of small-sized fuel cells for mobile electric devices. In general, a water cooling system requires a valve for controlling flow rate of coolant in order to keep targeted devices at appropriate working temperature. Traditional type of a flow control valve is driven by an external power source and a control system. However, for the realization of small-sized fuel cells, it is preferable that whole water cooling system is sufficiently small and can be driven by very little or no electricity. Therefore, in this paper, we focus on a thermal actuated compliant mechanism as the successor to the traditional type of a flow control valve and develop an optimal design method of a thermal actuated compliant valve based on our two-stage design method that consists of topology and shape optimization. In the 1st stage, topology optimization creates an initial outline of a thermal actuated compliant valve. To allow for design of thermal actuator, we adopt level set based topology optimization and formulate the thermal actuator design problem as a topology optimization problem. In the 2nd stage, shape optimization then yields detailed shape of a thermal actuated compliant valve by considering various design requirements of a flow control valve such as ratio of valve opening due to temperature change and stress constraints.
