Conjugate heat transfer of impingement cooling using conical nozzles with different schemes in a film-cooled blade leading-edge

• Published in: Applied thermal engineering Vol. 177; p. 115491
• Main Authors: Fawzy, Hamza, Zheng, Qun, Jiang, Yuting, Lin, Aqiang, Ahmad, Naseem
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2020; Elsevier BV
• Subjects: Computer simulation; Conical nozzle; Conical nozzles; Conjugate heat transfer; Conjugates; Cooling; Cooling effects; Film cooling; Finite element method; Fluid flow; Heat transfer; Impingement; Impingement cooling; K-omega turbulence model; Leading-edge; Nozzles; Reynolds number; Temperature; Temperature ratio; Conical nozzle; Leading-edge; Conjugate heat transfer; Film cooling; Impingement cooling
• ISSN: 1359-4311; 1873-5606
• DOI: 10.1016/j.applthermaleng.2020.115491

•Effect of using conical nozzles is studied for different conjugate impingement cooling schemes.•Different Reynolds numbers and temperature ratios are applied for all simulations.•The staggered conical model achieves the highest internal and external cooling performance.•The external cooling performance is mainly affected by the internal cooling of a leading-edge. In this paper, the effect of utilizing different schemes of conical nozzles for impingement cooling is studied in the conjugate heat transfer in a film cooled blade leading-edge. Three conjugate cooling schemes (tangential, inline normal, staggered normal) are analyzed and compared at different nozzle Reynolds numbers from 5000 to 25,000 and different temperature ratios from 0.5 to 0.85. The SST k-Omega turbulence model and a very fine unstructured mesh are validated and applied for all simulations. Based on the design, the staggered normal scheme can protect the most critical zone of a blade subjected to the highest temperature (stagnation area) better than the other cooling schemes. The internal cooling performance increases with the nozzle Reynolds number under a fixed temperature ratio. At identical nozzle Reynolds number, the internal heat transfer increases with the temperature ratios from 0.5 to 0.675 while it decreases over 0.675 up to 0.85. The staggered normal scheme achieves an increase in overall Nusselt number by 5.26–9% and by 9.78–21.27% compared to the tangential scheme and inline normal scheme, respectively over the applied range of nozzle Reynolds number. The staggered normal scheme achieves the highest cooling performance internally and externally among the other cooling schemes.