| Autor: |
I. M. Khalifa, G. E. Andrews |
| Rok vydání: |
2013 |
| Předmět: |
|
| Zdroj: |
Volume 3B: Heat Transfer. |
| DOI: |
10.1115/gt2013-95355 |
| Popis: |
Full coverage effusion cooling was studied for a square array of 90° effusion cooling holes with backside cooling using a 5 mm depth duct air supply to the coolant holes, with the duct air mass flow rate being greater than the effusion cooling flow. This geometry represents combustor primary zone wall cooling with the dilution air or main combustion air comprising the excess backside flow rate. Active cooling was used with metal walls and 300K effusion cooling into a 27 m/s mean velocity duct flow at 770K crossflow temperature. The aim was to provide conjugate heat transfer experimental data to validate conjugate heat transfer CFD prediction procedures. The 152 mm square test section had 15 rows of holes The X/D value studied was 11.0, which gives a 3% effusion wall pressure loss at a relatively low effusion coolant mass flow rate. The duct air feed to the holes enhanced the backside cooling of the wall. These results were compared with previous work using a plenum chamber air feed and with a crossflow duct, but with equal cross flow air to effusion air. The increased duct air feed velocity relative to the plenum low velocity air feed resulted in an increase in the overall cooling effectiveness due to the additional heat transfer by the duct crossflow velocity. This effect was across the whole duct length when there was surplus cross flow air relative to effusion air, without this the enhanced heat transfer was small and confined to the leading edge area. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
