Thesis VALIDACIÓN DE LA UTILIZACIÓN DE LA HIPÓTESIS DE BOUSSINESQ EN LAS SIMULACIONES DE FLUJOS DE CONVECCIÓN NATURAL EN UNA CAVIDAD DIFERENCIALMENTE CALENTADA
Date
2019-10
Authors
PLAZA RETAMALES, GUSTAVO ALEJANDRO
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Abstract
En la presente memoria de titulación, se estudió mediante simulación la validez de la hipótesis de Boussinesq en una cavidad diferencialmente calentada con relación de aspecto de 4 a distintos números de Rayleigh en convección natural. Para ello se utilizó el programa Ansys Fluent 19.2 Academic, con una malla de 500.000 nodos aproximadamente, dos modelos de viscosidad turbulenta LESWALE y K-Omega SST, algoritmo de presión SIMPLE y PISO respectivamente con solver basado en presión. No fue posible
obtener resultados estables en el tiempo para el modelo viscosidad turbulenta LES WALE y el estudió se basó solo en los resultados de K-Omega SST. Se evidenció leves diferencias en los perfiles de velocidad u y v, como también en los contornos de temperatura, viscosidad de eddy y energía cinética turbulenta dando errores del rango de 0.3% a 6.7 %, por lo que se concluyó que la hipótesis es válida en el dominio de la cavidad para los números de Rayleigh y condiciones estudiados.
In the present degree work, the validity of the Boussinesq hypothesis in a differentially heated cavity with an aspect ratio of 4 to different Rayleigh numbers in natural convection was studied by simulation. For this, the Ansys Fluent 19.2 Academic program was used, with a mesh of approximately 500,000 nodes, two models of turbulent viscosity LES WALE and K-Omega SST, pressure algorithm SIMPLE and PISO respectively with pressure based solver. It was not possible to obtain stable results over time for the LES WALE turbulent viscosity model and the study was based only on the results of K-Omega SST. Slight differences were observed in the u and v velocity profiles, as well as in the contours of temperature, eddy viscosity and turbulent kinetic energy giving errors in the range of 0.3% to 6.7% , so it was concluded that the hypothesis is valid in the cavity domain for Rayleigh numbers and conditions studied.
In the present degree work, the validity of the Boussinesq hypothesis in a differentially heated cavity with an aspect ratio of 4 to different Rayleigh numbers in natural convection was studied by simulation. For this, the Ansys Fluent 19.2 Academic program was used, with a mesh of approximately 500,000 nodes, two models of turbulent viscosity LES WALE and K-Omega SST, pressure algorithm SIMPLE and PISO respectively with pressure based solver. It was not possible to obtain stable results over time for the LES WALE turbulent viscosity model and the study was based only on the results of K-Omega SST. Slight differences were observed in the u and v velocity profiles, as well as in the contours of temperature, eddy viscosity and turbulent kinetic energy giving errors in the range of 0.3% to 6.7% , so it was concluded that the hypothesis is valid in the cavity domain for Rayleigh numbers and conditions studied.
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TURBULENCIA , CALOR TRANSMISION , MECANICA DE FLUIDOS