Session: 15-01 Jet Impingement

Paper Number: 82346

82346 - Experimental Investigation on Heat Transfer Characteristics in an Impingement/Effusion Cooling System of a Ribbed Turbine Casing 

Current paper reports an arrays of impinging jets cooling structure applied to the turbine casing. The structure consists of three rows of impingement holes and two rows of effusion holes, both the impingement holes and effusion holes are staggered arrangement. A supporting high rib inside the impingement cavity, which is connected to the target wall and divides the impingement cavity into two interconnected chambers, one of which is arranged with two rows of impingement holes and effusion holes, while the other chamber is arranged without effusion holes, so part of the cooling airflow has to flow out from the outflow holes across the high rib.An  Investigation combined numerical simulation and transient liquid crystal (TLC) technology was conducted to obtain detailed flow and heat transfer characteristics data under the influence of jet-to-target distance(H/D) and hole arrangement at low Reynolds number. The range of Reynolds number defined by impingement hole diameter is Re_D=1100-5100,  the range of jet-to-targrt distance(H/D) is 2.5-7.5, and the impingement hole spacing(C/D) ranges from 8.0-14.0. The results show that: within the uncertainty range of the experiment, the numerical simulation are in good agreement with the experimental results. Unlike the turbulate ribs that enhance heat transfer, the high ribs do not enhance heat transfer but the heat transfer coefficient at the root of the rib is very low. Increasing the jet Reynolds number can significantly improve the surface average heat transfer coefficient. From the heat transfer coefficient distribution, the enhanced heat transfer effect of the Reynolds number is not obvious in some areas. As the jet to plate distance increases, the average heat transfer coefficient of the target surface shows a decreasing trend. However, from the detailed heat transfer coefficient distribution, the jet to target distance on the heat transfer coefficient is limited to the impingement stagnation point 2D. As the distance between the impingement holes increases, the ratio of the surface that can be effectively cooled by the wall jet to the entire heat exchange surface gradually decreases, and the heat transfer coefficient of the target surface gradually decreases.

Presenting Author: Guodong Li Northwestern Polytechnical University

Presenting Author Biography: Guodong Li, PhD student, mainly engaged in heat transfer and cooling technology of aero-engine hot-end components

Authors:

Guodong Li Northwestern Polytechnical University
Tao Guo Northwestern Polytechnical University
Changbo Qiu AECC Hunan Aviation Powerplant Research Institute
Cunliang Liu Northwestern Polytechnical University
Huiren Zhu Northwestern Polytechnical University
Jichen Li Northwestern Polytechnical University