Helical static mixer simulations for its integration in the pour plate method: mixing agar and a nutrient solution

In microbiology laboratories, it is essential to obtain high-quality samples where the culture media are completely homogeneous. The pour plate method includes having to melt the culture media—a mixture of agar and a nutrient solution—before seeding. A static mixer is designed for this purpose, empl...

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Detalles Bibliográficos
Autores: Diaz Font, Ana M., Terrones Fernández, Inés, Gámez Montero, Pedro Javier|||0000-0002-5168-3521, Castilla López, Roberto|||0000-0002-3848-2004
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/393089
Acceso en línea:https://hdl.handle.net/2117/393089
https://dx.doi.org/10.3390/en16155816
Access Level:acceso abierto
Palabra clave:Fluid dynamics
Computational fluid dynamics
Laminar flow
Viscosity
Static mixer
Helical mixer
Computational Fluid Dynamics (CFD)
High viscosity ratio
Miscible liquids
Mixing index
Agar-nutrients
Pour plate
Dinàmica de fluids
Dinàmica de fluids computacional
Flux laminar
Viscositat
Àrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids
Descripción
Sumario:In microbiology laboratories, it is essential to obtain high-quality samples where the culture media are completely homogeneous. The pour plate method includes having to melt the culture media—a mixture of agar and a nutrient solution—before seeding. A static mixer is designed for this purpose, employing CFD (Computational Fluid Dynamics) with the software OpenFOAM to simulate the fluid’s behaviour in a helical static mixer with both internal and external configurations. The objective is to validate the CFD model by comparing it with the literature and provide a first approach to the mixer design. After satisfactory validation of the model, the results of the initial designs for Reynolds number 14 reveal the notably different behaviour of the fluids during mixing due to their differing properties, since agar and the nutrient solution present a high viscosity ratio. While the mixing efficiency is similar for the internal and external mixers, improved performance is demonstrated in the internal mixer, even for a shorter version. The external version of the mixer reaches a value for a mixing efficiency of 0.89 whereas the internal version performs more homogeneous mixing for the same number of mixing elements. This evaluation is based on a simplified internal design for computational simulations, whereas the external mixer is easier to manufacture but more complex to implement computationally. Finally, homogeneous mixing is achieved for the internal mixer configuration when adjusting its dimensions to those available on the market