  In this study, in order to reduce the local high temperature of the platform
in inertial navigation system (PINS), a pin-fin heat sink with staggered
arrangement is designed. To reduce the dimension of the inputs and improve the
efficiency of optimization, a feasible global sensitivity analysis (GSA) based
on Kriging-High Dimensional Model Representation with DIviding RECTangles
sampling strategy (DIRECT-KG-HDMR) is proposed. Compared with other GSA
methods, the proposed method can indicate the effects of the structural and the
material parameters on the maximum temperature at the bottom of the heat sink
by using both sensitivity and coupling coefficients. From the results of GSA,
it can be found that the structural parameters have greater effects on thermal
performance than the material ones. Moreover, the coupling intensities between
the structural and material parameters are weak. Therefore, the structural
parameters are selected to optimize the thermal performance of the heat sink,
and several popular optimization algorithms such as GA, DE, TLBO, PSO and EGO
are used for the optimization. Moreover, steady thermal response of the PINS
with the optimized heat sink is also studied, and its result shows that the
maximum temperature of high temperature region of the platform is reduced by
1.09 degree Celsius compared with the PINS without the heat sink.
