No abstract

No abstract

Purpose -The paper aims to focus on airflow and heat transfer inside the human nasal cavity. The contribution of this work is the inertial analysis of the momentum and thermal stress of the cavity throughout the respiratory cycle. Design/methodology/approach -By means of computer tomography scans, an accurate three-dimensional anatomical representation of the human nasal cavity was obtained. A three-dimensional numerical model is presented in order to predict the time evolution of flow patterns during a quiet breathing cycle, covering inhalation and exhalation. An inertial analysis of the momentum and a detailed study of the thermal behaviour during the breathing cycle is carried out. Findings -Head loss, velocity and temperature values are in agreement with experimental results from previous studies. Based on these results, the influence of the inhalation and the exhalation on the flow pattern and air conditioning has been reviewed. Results suggest that the anterior and posterior turbinate regions are where the air conditioning is primarily produced. Practical implications -The future goal is to investigate respiratory disorders to increase the effectiveness of the eventual treatment of the pathology. The model could be a useful tool to predict, for instance, the modification of the flow patterns due to septal perforations. Originality/value -The transient resolution provides insight into the momentum and thermal inertia though the breathing which is far from being well understood.

El combustible empleado en las máquinas y equipos térmicos usados en las diversas actividades productivas de los sectores transporte, minería, energía, otros; es el petróleo diesel 2, que al poseer niveles altos de azufre y ejecutarse la combustión, se produce bióxido de azufre (SO2) o partículas de sulfatos, por eso es difícil reducir la contaminación del aire generada por el uso de petróleo diesel 2, sin eliminar el azufre en su formulación; e impide el uso de muchas tecnologías convencionales y avanzadas para el control de contaminantes, incluyendo monóxido de carbono (CO), partículas (PM), óxidos de nitrógeno (NOx) e hidrocarburos (HC). En este trabajo, se comprueba experimentalmente el impacto del empleo de petróleo diesel 2, que posee elevado contenido de azufre en su formulación, sobre los componentes del sistema de inyección diesel del motor diesel turboalimentado con control electrónico Caterpillar 3412, modelo HEUI; se realiza la medición micrométrica del desgaste de la tobera del inyector y del vástago impulsor del inyector, se visualiza los vestigios de erosión y picaduras en los asientos de la válvula poppets y del inyector.