Turbocharger has been widely implemented for internal combustion engine to increase an engine's power output and reduce fuel consumption. However, its operating temperature would rise to 340°C when engine stalls. This higher temperature may results in bearing wear, run-out, and stick, due to oil coking and insufficient lubrication. In order to overcome these problems, this paper employs Electric Water Pump (EWP) to supply cool liquid to turbocharger actively when the engine stalls. The system layout, operating timing, and duration of EWP are investigated for obtaining optimal performance. The primarily experimental results show that the proposed layout and control strategy have a lower temperature of 100°C than the conventional temperature 225°C.

This study applied the commercial software ANSYS CFD (FLUENT), for simulating the transient flow field and investigating the influence of each parameter of longitudinal vortex generators (LVGs) on the thermal flux of a plate-fin heat sink. Vortex generator was set in front of plate-fin heat sink and under the channel, which was in common-flow-down (CFD) and common-flow-up (CFU) conditions, which have the result of vortex generator of delta winglet pair (DWP). In this study the parameters were varied, such as the minimum transverse distance between winglet pair, the attack angle of the vortex generator, fins number, the fin height, and the distance between the vortex generator and plate-fin. The coolant fluid flew into the fin-to-fin channel and pushed the vortex from different geometry toward the bottom. This phenomenon took off the heat from the plate to enhance the heat transfer. The numerical results indicated that the LVGs located close to the plate-fin heat sink are zero with the attack angle being 30°, presenting optimal overall conditions.

Applying software Ansys-Fluent to analysis the effect of piezoelectric fan device installed inside rectangular channel by numerical simulation method. The piezoelectric fan is activated by reversible piezoelectric effect in piezoelectric material, change rectangular channel flow field construction, then it affects heat flow status in advance. Numerical simulation parameter are included Nusselt number (Nu), distance between peak of fan blades to front part of heat sink (L g =0, 5, 10, -11.25, -22.5, -33.75, -45), height from center on piezoelectric fan bottom side (H w =10, 16, 21), number of piezoelectric fan (single-fan and twin-fan), phase-shift (in-phase and counter-phase), and numbers (n=10, 14) for heat sink fin. This result is indicated that good position to temperature dropped greatly is located from the front part of piezoelectric fan to the front of heat sink (L g = -22.5) under fixes distance (H w = 21) from piezoelectric fan to channel also found to provide double piezoelectric fan heat drop effect is equal to single one, however, double piezoelectric fans would provide higher heat dissipation as Counter-phase. The performance of piezoelectric fan is improved depends on change height (H w ) from center of piezoelectric fan to channel bottom; the height (H w ) shall be decreased as piezoelectric fan placement at the front of heat sink.