Heat Transfer Characteristics Within an Array of Impinging Jets. Effects of Crossflow Temperature Relative to Jet Temperature


Book Description

Spanwise average heat fluxes, resolved in the streamwise direction to one stream-wise hole spacing were measured for two-dimensional arrays of circular air jets impinging on a heat transfer surface parallel to the jet orifice plate. The jet flow, after impingement, was constrained to exit in a single direction along the channel formed by the jet orifice plate and heat transfer surface. The crossflow originated from the jets following impingement and an initial crossflow was present that approached the array through an upstream extension of the channel. The regional average heat fluxes are considered as a function of parameters associated with corresponding individual spanwise rows within the array. A linear superposition model was employed to formulate appropriate governing parameters for the individual row domain. The effects of flow history upstream of an individual row domain are also considered. The results are formulated in terms of individual spanwise row parameters. A corresponding set of streamwise resolved heat transfer characteristics formulated in terms of flow and geometric parameters characterizing the overall arrays is described.













Jet Array Impingement with Crossflow - Correlation of Streamwise Resolved Flow and Heat Transfer Distributions


Book Description

Correlations for heat transfer coefficients for jets of circular offices and impinging on a surface parallel to the jet orifice plate are presented. The air, following impingement, is constrained to exit in a single direction along the channel formed by the jet orifice plate and the heat transfer (impingement) surface. The downstream jets are subjected to a crossflow originating from the upstream jets. Impingement surface heat transfer coefficients resolved to one streamwise jet orifice spacing, averaged across the channel span, are correlated with the associated individual spanwise orifice row jet and crossflow velocities, and with the geometric parameters. (NTRL site)




A Study on Flow and Heat Transfer Characteristics of Geometrically Innovative Impinging Jets


Book Description

It was found in the case of the former nozzle that main and secondary peaks of the Nusselt number distributions around the stagnation region were merged into a single peak as the extension collor length was increased, regardless of the oscilllating frequency. The latter case was found to enhance heat transfer from a spanwisely much wider area, compared with the case of the conventional impinging jet nozzle normal to the target wall. The enhanced area of heat transfer corresponds very well to the behaviors of the longitudinal vortices. [Authors' abstract].