Affiliation:
1. Universidad Autónoma Metropolitana
Abstract
In this work a Schlieren system is proposed. It is used to visualizing a convection flow, caused by the cooling surface a Peltier cell. The experimental assembly elements are a white LED light source (450 nm – 650 nm) that consumes 300 nW of measured electrical power, a Z-type optical reflective relay, a knife, an image acquisition system based on an Edmund EO02018C camera with CMOS RGB sensor and optomechanical components. A program for the analysis of the reference and the convection flow video was designed. As a first step, numerical integration and the phase unwrapping were carrid out to obtain the temperature gradients of the phenomenon under study and its temporal evolution. Then, each detection layer was analyzed, processing the data that provide more information on this phenomenon. It is important to note that the red layer of the camera has a better contrast in the visualization of the phenomenon, however, it is more affected by undesirable light diffraction. Therefore, the green layer of the camera is optimal for analyzing the phenomenon, this study confirms that that the Schlieren technique is ideal for observing phenomena where the temperature gradient is small and there are convection flows.
Reference10 articles.
1. Aguilar Fernández, E., Gómez Vieyra, A., Miranda Tello, J. R., & Álvarez Herrera, C. (2014). Instrumentación de un Sistema Schlieren Unidimensional para la Adquisición de los Mapas de Gradiente de Temperatura (pp. 1–7). Puerto Vallarta, Jalisco: SOMI.
2. Alvarez-Herrera, C., Moreno-Hernández, D., & Barrientos-García, B. (2008). Temperature measurement of an axisymmetric flame by using a Schlieren system. Journal of Optics A: Pure and Applied Optics, 10(10), 104014. https://doi.org/10.1088/1464-4258/10/10/104014
3. Alvarez-Herrera, C., Moreno-Hernández, D., Barrientos-García, B., & Guerrero-Viramontes, J. A. (2009). Temperature measurement of air convection using a Schlieren system. Optics & Laser Technology, 41(3), 233–240. https://doi.org/10.1016/j.optlastec.2008.07.004
4. Alvarez-Herrera, C., Murillo-Ramírez, J. G., Pérez-Reyes, I., & Moreno-Hernández, D. (2015). Proper orthogonal decomposition applied to laminar thermal convection in a vertical two plate channel. Journal of Optics, 17(6), 65602. https://doi.org/10.1088/2040-8978/17/6/065602
5. Cisneros Martínez, J. A. (2015). Medición de la temperatura mediante un sistema Schlieren monocromático para analizar procesos de combustión. División de Ciencias Básicas e Ingeniería. Universidad Autónoma Metropolitana, México, D. F.