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Numerical Calculation of the Irreversible Entropy Production of Additively Manufacturable Off-Set Strip Fin
Marco Fuchs1, Nico Lubos1, Stephan Kabelac1
1Institute of Thermodynamics, Leibniz University Hannover, An der Universität 1, 30823 Garbsen, Germany.
Entropy (Basel, Switzerland)
|January 21, 2023
Summary
Additive manufacturing enables novel off-set strip fin structures. Optimizing fin length and displacement enhances heat transfer and reduces entropy production, crucial for efficient thermal management.
Area of Science:
- Thermodynamics
- Fluid Mechanics
- Heat Transfer
Background:
- Additive manufacturing offers new possibilities for creating complex heat exchanger geometries.
- Off-set strip fins are a common design for enhancing heat transfer.
- Understanding entropy production is key to optimizing energy efficiency in thermal systems.
Purpose of the Study:
- To investigate the thermal-hydraulic performance of additive-manufactured off-set strip fin structures.
- To analyze the impact of geometric parameters on heat transfer and pressure drop.
- To evaluate entropy production as a metric for optimizing fin design.
Main Methods:
- Numerical calculation of Colburn j-factor and Fanning friction factor for varying geometric parameters (fin height, spacing, length, longitudinal displacement).
- Classification of structures using Bejan's entropy production number.
- Comparison with partial differential equation-based calculations for irreversible entropy production.
Main Results:
- Fin height and spacing have minimal impact on heat transfer and pressure drop.
- Fin length and longitudinal displacement significantly influence performance.
- Short and long fins, along with large fin spacing and displacement, are beneficial for reducing entropy production.
- Entropy production due to heat conduction is primarily driven by the wall, with minor fluid influence.
Conclusions:
- Additive manufacturing allows for the design of optimized off-set strip fins.
- Fin length and longitudinal displacement are critical parameters for enhancing thermal performance and minimizing irreversibility.
- Entropy production analysis provides valuable insights for designing more efficient heat exchangers.
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