A numerical investigation on heat transfer and emissions characteristics of impinging radial jet reattachment combustion (RJRC) flame. (5th October 2015)

• Record Type: Journal Article
• Authors: Tajik, Abdul Raouf; Hindasageri, Vijaykumar
• Is Part Of: Applied thermal engineering. Volume 89(2015:Oct.)
• Page Start: 534
• Page End: 544
• Publication Date: 2015-10-05
• Subjects: Heat flux -- Emissions -- RJRC -- CFD -- Turbulence; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2015.06.044
• Languages: English
• ISSNs: 1359-4311

Abstract

Abstract: Radial Jet Reattachment combustion (RJRC) flame jet is used in applications where the impingement surface is delicate and demands low impingement pressure. In the present study, a two dimensional axisymmetric computational fluid dynamics (CFD) simulation is carried out. The turbulence–combustion interaction in the flame field is modeled in a k−ε/EDM framework. The distribution of heat flux, pressure coefficient and emissions is presented for varying Reynolds number ( Re = 1000 to 30, 000) and different non-dimensional nozzle tip to plate spacing ( X/R = 0.5 to 3). It is found that the peak heat flux increases and pressure coefficient reduces significantly with the increase in Reynolds number. However, with the increase in the nozzle tip to plate spacing the peak heat flux and the pressure coefficient decrease. Furthermore, the concentrations of NOx and CO emissions increase with the increase in Reynolds number and the distance of the location of the nozzle tip from the impingement plate. Highlights: Effect of Re and X/R is studied on heat transfer and emissions characteristics. At higher Re, increased turbulence intensity is responsible for higher heat flux. At larger X/R, the heat flux decrease as the distance of hot spots from the plate increases. At larger X/R, the relatively larger eddy length scale results in improved mixing. The NOx increases with increase in both Re and X/R.