SARA RAINIERI

University of Parma

Enhancing Heat Exchanger Performance: Integrating Numerical Modeling with Experimental Studies for Optimization Approaches

BIO

Born in Fidenza, Parma, Italy (1969), graduated summa cum laude in Physics at the University of Parma, PhD in Applied Physics (1997), post-doc fellowship at the University of Parma (1997- 1998) and at the University of Bologna (1999), University Researcher (1999), Associate Professor (2002) and Full Professor (2015) in Applied Physics at the Department of Engineering and Architecture of the University of Parma. Honourable mention for the Ph.D. thesis within the EUROTHERM Young Scientist Prize and Awards 2000. Pro-Rector for Education and Student Affairs at the University of Parma, Italy (2017-2023). President of the Italian Union of Thermal Fluid Dynamics (2023-2025). President of the Italian Association of Applied Physics (2023-2025). Best Associate Editor (2022) for the ASME Journal of Heat Transfer. National coordinator of the project PRIN2022 "MOOD4HEX - MOrphology Optimized Design for Heat EXchangers", founded by the Italian Ministry within the National Recovery and Resilience Plan. The research activity is focused mainly on these main following topics: techniques for the heat transfer enhancement in forced convection, with specific reference to challenges in the food industry, solution techniques of inverse heat transfer problems, with both theoretical and experimental approaches, innovative data processing and parameter estimation procedures based on infrared thermographic mapping, optimization approaches of energy performance in integrated systems.

 

ABSTRACT

One significant challenge continually encountered by manufacturers of heat exchangers is the imperative for a design approach grounded in technological innovation aimed at producing devices that are not only more thermally efficient but also feature reduced pressure drop, volume, manufacturing and operational costs, and high-quality surface finishing to mitigate fouling phenomena. A strategy that has been successfully explored in literature to achieve this goal consists in the use of emerging additive manufacturing technologies, that enable to produce surfaces with an optimized morphology. This challenge requires a multidisciplinary approach that couples the advantages of numerical approaches to experimental advanced measurement and data processing procedures, mostly based on highly resolved infrared thermographic systems. The possibility of obtaining detailed information about the heat transfer capability of enhanced surfaces can be suitably achieved by using numerical tools in the optimization problem that adopts experimental data as a necessary either input or validation elements. One exemplificative and interesting example is found in the use of infrared thermography to acquire highly spatially resolved temperature maps on the external surface of heat exchanger’s sections for numerically solving the inverse heat conduction problem in the solid wall for estimating the local heat transfer coefficient at the fluid-internal wall interface. This detailed information, coupled to the numerical evidence of the fluid’s velocity distribution within the device, is essential for several engineering applications. For instance, in the thermal processing of fluid foods, that have to accurately achieve the required microbial load reduction that is governed by the local temperature history of the fluid particles and not only on the average overall heat transfer capability of the device. Another interesting application of the here addressed methodology is found in the optimal design of passive heat transfer enhancement techniques to be adopted in forced convection heat transfer, such as the ones based on the morphological optimization of inserts to be adopted in tubular heat exchangers. Numerical CFD simulations coupled to the adjoint approach have for instance provided a flexible and effective tool to verify the optimal geometry that enables to maximize the objective function, i.e. the thermal performance to pressure drop penalties ratio, for butterfly-shaped inserts.