Among numerous electronic cooling methods, a vibrating heat sink using sinusoidal wave vibration effectively enhances the heat transfer by disturbing the thermal boundary layer. However, sinusoidal wave vibration has reached its limits in enhancing heat transfer. The present study utilizes a new square wave-shaped vibration and numerically investigates the thermal performance of a heat sink subjected to sinusoidal and square waves vibration. It is found that using the square wave vibration is more beneficial to the thermal performance of the heat sink than the sinusoidal wave. The sudden impulsive motion of square wave vibration induces a higher randomness of the airflow profile and recirculation zones than the sinusoidal wave, causing the air flow to impinge directly into the fin surfaces, and further enhances the heat transfer. Furthermore, increasing the frequency and amplitude leads to a higher heat transfer enhancement. Moreover, square wave vibration achieves a 25% increase in Nusselt values compared to the nonvibrating fins and it is 11% higher than the Nusselt number recorded by the sinusoidal vibration. Consequently, Reynolds number values can be reduced by 42.2% to achieve the Nusselt number values of nonvibrating fins, potentially reducing the cooling system or fin size. This reduction may contribute to solving the challenges of electronic systems compactness.

In standard district cooling (DC) plants, central chillers produce cold energy for space cooling throughout the district network. In recent times, the integration of the vapor compression system, which includes the functionalities of vapor compression chillers (VCC), and thermal energy storage (TES) tanks in the DC setup, has gained more implementation across the globe. This is due to the possibility of load shifting by using the VCC to produce chilled water for charging the TES tanks during off peak periods. Since the environmental implications of various energy intensive systems are largely determined by the amount of material and energy consumed throughout their life cycle, it is critical to conduct a sustainability assessment of these systems in terms of environmental contributions, and suggest design options to reduce these impacts. A cradle to grave life cycle assessment (LCA) model is created in response to these issues and in order to meet the project’s objectives. The life cycle impact assessment (LCIA) results of the analysis reveal that the carbon footprint per 1 RTh of the produced chilled water is estimated at 0.72 kg CO₂ eq/RTh. The operation phase of the system’s life cycle accounted for the most impact, about 98%, with other life cycle phases having negligible contributions. In substantiating the study’s investigation, the environmental performance based on several design options were discussed and compared to the case study. Among the several scenarios considered, incorporating the Sweden mix technology provided the case study with the most significant environmental savings, of about 94%.

Applying sinusoidal vibration to heat sinks has proven to be a promising technique for improving heat transfer by disrupting the thermal boundary layer. However, applying sinusoidal vibration to the base of thin plate-fin heat sinks can cause a flapping motion within the fins, further enhancing heat transfer. Therefore, the current study numerically investigates and compares the effects of sinusoidal vibrations on the thermal performance of conventional and thin plate-fin heat sinks. The study concludes that increased vibrational amplitude and frequency (f ˃ 30 Hz) increases the vibration-assisted thermal performance. It was found that the thin plate-fin heat sink provides higher thermal performance compared to the conventional heat sink at every level of vibrational characteristics. The study found that the application of vibration enhances the Nusselt number up to a maximum of 20% and 15% in thin plate-fin and conventional heat sinks, respectively. Furthermore, the Reynolds number is reduced by 33.3% and 28% with thin plate-fin and conventional heat sinks compared with non-vibrating heat sinks, indicating a potential reduction of the size of the cooling system or fin size.

The application of vibration on a heated surface is found to be one of the promising cooling methods. Previous studies found that the thermal performance of the heated body depends on the vibrational characteristics and wave shape. However, for heat sinks, the direction of the vibration for different vibrational wave shapes has not been investigated, which may influence cooling. Thus, the current study conducted a numerical investigation to study the effect of the vibration direction of sinusoidal and square wave shaped vibration on the conventional heat sink and validated it against experimental results with a maximum deviation of 2.4%. The study is conducted with a range of frequencies and peak-to-peak amplitude of 0-80 Hz and 0-0.005 m under the square and sinusoidal wave shapes. It was found that the Nusselt number increases with higher frequencies (f>40 Hz), and amplitudes and enhancement in Nusselt values are more dominant with square wave shapes. At the vibration frequency and peak-to-peak amplitude of 80 Hz and 0005 m, a maximum of 9.3 % and 7.2 % enhancement in the Nusselt number is recorded with square and sinusoidal vibration, respectively. Moreover, the result of the current study is compared with the published work, and it was concluded that the effect of vibration on heat transfer is superior to horizontal vibration in comparison with vertical vibration by 7% and 3.2% under square and sinusoidal wave shaped vibrations, respectively