title: Evaluation of Computational Fluid Dynamics and Coupled Fluid-Solid Modeling for a Direct Transfer Preswirl System.
abstract: The prediction of the preswirl cooling air delivery and disk metal temperature are important for the cooling system performance and the rotor disk thermal stresses and life assessment. In this paper, standalone 3D steady and unsteady computation fluid dynamics (CFD), and coupled FE-CFD calculations are presented for prediction of these temperatures. CFD results are compared with previous measurements from a direct transfer preswirl test rig. The predicted cooling air temperatures agree well with the measurement, but the nozzle discharge coefficients are under predicted. Results from the coupled FE-CFD analyses are compared directly with thermocouple temperature measurements and with heat transfer coefficients on the rotor disk previously obtained from a rotor disk heat conduction solution. Considering the modeling limitations, the coupled approach predicted the solid metal temperatures well. Heat transfer coefficients on the rotor disk from CFD show some effect of the temperature variations on the heat transfer coefficients. Reasonable agreement is obtained with values deduced from the previous heat conduction solution.
authors: e-mail:  u.javiya@surrey.ac.uk.
authors: Umesh
authors: U
authors: Javiya
authors: e-mail:  j.chew@surrey.ac.uk.
authors: John
authors: J
authors: Chew
authors: e-mail:  n.hills@surrey.ac.uk Thermo-Fluid Systems UTC , Faculty of Engineering and Physical Science , University of Surrey , Guildford, Surrey , GU2 7XH , UK.
authors: Nick
authors: N
authors: Hills
authors: Institut für Thermische Strömungsmaschinen (ITS) , Karlsruhe Institute of Technology , 76128 Karlsruhe , Germany e-mail:  klaus.dullenkopf@skit.edu.
authors: Klaus
authors: K
authors: Dullenkopf
authors: PO Box 31 , Rolls-Royce Plc, Derby , UK e-mail:  timothy.scanlon@rolls-royce.com.
authors: Timothy
authors: T
authors: Scanlon