Journal of Thermal Energy Systems

Thermal Performance Evaluation of 45° Ribbed and Dome-Enhanced Serpentine Cold Plates for Battery Thermal Management under Laminar Flow Conditions

2026-07-01T10:36:12+00:00

Thermal management of lithium-ion batteries is critical to ensure operational safety, electrochemical stability, and lifecycle performance in electric vehicles. Under laminar flow conditions typical of battery cooling systems, smooth serpentine cold plates often exhibit limited convective heat-transfer performance. In this study, a three-dimensional, steady-state numerical investigation was conducted to evaluate the effectiveness of 45° rib- and dome-based passive enhancement strategies in improving thermal performance. Serpentine cold plates incorporating triangular, trapezoidal, semi-circular ribs, and dome structures were analysed under a uniform heat flux of 30,000 W/m² applied to the bottom surface of a copper plate, while the top surface was maintained adiabatic. Water at 21°C was used as the coolant, and simulations were performed for Reynolds numbers ranging from 200 to 1000 under laminar flow conditions. Thermal performance was quantified using the Nusselt number, convective heat transfer coefficient, and convective thermal resistance. Results indicate that all enhanced geometries improved heat transfer relative to the smooth channel, particularly beyond Re = 400. At Re = 1000, the semi-circular rib configuration achieved a maximum Nusselt number of 44.85 compared to 26 for the smooth case, corresponding to a 72.5% enhancement. The convective heat transfer coefficient increased from 2733 to 4713 W/m²K, while convective thermal resistance decreased by approximately 41.8%. These findings confirm that 45° rib-induced flow disturbance significantly enhances convective heat transfer under laminar conditions, with semi-circular ribs providing the most effective passive thermal enhancement for high-performance battery thermal management systems.

Multi-Criteria Analysis of Solar Energy Expansion Pathways in Bangladesh for Achieving Net-Zero Emission Targets

2026-07-02T08:31:23+00:00

Achieving net-zero emission targets has become a critical priority for Bangladesh, driven by increasing energy demand, climate vulnerability, and dependence on fossil fuel imports. Although solar energy offers significant potential for decarbonization, multiple expansion pathways exist, each with distinct trade-offs related to cost, land use, reliability, and policy feasibility. The lack of a structured framework to evaluate these alternatives creates challenges for effective energy planning. This study addresses this gap by applying a multi-criteria decision-making approach to identify the most suitable solar energy expansion pathway for Bangladesh. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is employed to evaluate five alternatives: utility-scale solar, rooftop solar, floating solar, agrivoltaics systems, and hybrid solar systems with storage. A comprehensive set of criteria encompassing technical, economic, environmental, and socio-political dimensions is considered, with equal weighting to ensure methodological transparency and reproducibility. The results indicate that hybrid solar systems with storage rank highest, followed by rooftop solar systems, highlighting the critical importance of reliability and land-use efficiency in Bangladesh’s energy transition. Utility-scale solar, while significant in capacity, is constrained by land and economic factors, whereas emerging technologies such as floating solar and agrivoltaics show long-term potential but currently face implementation challenges. The findings provide actionable insights for policymakers, emphasising the need to prioritise hybrid and distributed solar systems, strengthen policy frameworks, and invest in grid modernisation and energy storage to support a sustainable pathway toward net-zero emissions.