Turbulent mixing enhancement with a 10° chute mixer

Abstract

Purpose

Turbulent mixing of two co‐axial jets having a low annular to core area ratio is enhanced by employing a chute mixer, directing part of the annular stream at 10° towards the core region. Aims to present results from measurements of time‐averaged and fluctuating components of velocity under cold flow conditions.

Design/methodology/approach

Experiments were conducted at a bypass ratio of 0.47 which is a typical value for low bypass turbofan engines. Contours of time‐averaged velocity and streamwise and transverse turbulence intensities were obtained by making detailed measurements close to the chutes. Distributions of time‐averaged velocity and turbulence intensity were obtained at different axial locations downstream of the chute mixer. Total and static pressure measurements were also performed.

Findings

The high velocity annular stream was found to quickly diffuse after entering through the chutes and mix with the core stream due to high turbulence generation. A strong transverse turbulence component enhanced the mixing of the streams. With the aid of the chute mixer, nearly complete mixing is achieved over a length of 5 duct radii. A higher total pressure loss of about 1.38 percent is the penalty paid for the enhanced mixing.

Originality/value

Provides results from experiments into the process of turbulent mixing of co‐axial jets.

Citation

Ahmed, M.R. and Sharma, S.D. (2005), "Turbulent mixing enhancement with a 10° chute mixer", Aircraft Engineering and Aerospace Technology, Vol. 77 No. 5, pp. 404-414. https://doi.org/10.1108/00022660510617149