HIGH REYNOLDS NUMBER TRANSITION EXPERIMENTS IN THE ETW TEST FACILITY WITH THE PATHFINDER MODEL

Abstract: The Pathfinder model was designed in the course of the TELFONA European Research Project as a calibration tool to evaluate the transonic, cryogenic ETW facility for laminar flow testing, and assess the possibility for studies of NLF or HLF wings in ETW. The Pathfinder wing is a simplified, low taper, swept wing with an optimized profile allowing almost linear evolution of the N-factors in a wide range of flow conditions, especially designed for a precise estimation of transition N-factors. Temperature sensitive paint is used to allow optical detection of the transition location, and a series of pressure taps is used for measuring the pressure distribution. This general paper will cover model design, pre-test numerical evaluation, instrumentation and measurement methods, and will present a first set of cases selected for stability analysis and transition evaluation. Various tools for stability analysis and transition predictions will be tested, from local stability theory with the envelope methods to non-local theories taking into account curvature and non-local effects, based on the parabolized stability equations or on a multiple scale approach for compressible flows.

[1]  M. R. Malik,et al.  COSAL: A black-box compressible stability analysis code for transition prediction in three-dimensional boundary layers , 1982 .

[2]  Dan S. Henningson,et al.  Linear Nonlocal Instability Analysis - the Linear NOLOT Code - , 1995 .

[3]  Geza Schrauf,et al.  LARGE-SCALE LAMINAR FLOW TESTS EVALUATED WITH LINEAR STABILITY THEORY , 2001 .

[4]  W. Bartelheimer.  Ein Entwurfsverfahren für Tragflügel in transsonischer Strömung , 1996 .

[5]  Paolo Luchini,et al.  Application of the ray-tracing theory to the stability analysis of three-dimensional compressible boundary layers , 2006 .

[6]  Raffaele Donelli,et al.  Automatic Transition Predictions Using Simplified Methods , 2009 .

[7]  A. L. Braslow,et al.  History of Suction-Type Laminar-Flow Control with Emphasis on Flight Resrearch: Monographs in Aerospace History Number 13 , 1999 .

[8]  F. S. Collier,et al.  An overview of recent subsonic laminar flow control flight experiments , 1993 .

[9]  J. D. Crouch,et al.  Variable N-Factor Method for Transition Prediction in Three-Dimensional Boundary Layers , 2000 .

[10]  Jean Perraud,et al.  Comparison of Boundary-Layer Transition Predictions Using Flight Test Data , 1998 .

[11]  E. Eichelbrenner,et al.  Three-Dimensional Boundary Layers , 1973 .

[12]  Uwe Fey,et al.  The TELFONA Pathfinder Model, a second look , 2010 .

[13]  Uwe Fey,et al.  High Reynolds number transition detection by means of temperature sensitive paint , 2006 .

[14]  J. V. Ingen.  A suggested semi-empirical method for the calculation of the boundary layer transition region , 1956 .

[15]  G. Schrauf,et al.  Status and perspectives of laminar flow , 2005, The Aeronautical Journal (1968).

[16]  Uwe Fey,et al.  Transonic High Reynolds Number Transition Experiments in the ETW Cryogenic Wind Tunnel , 2010 .

[17]  François Laburthe.  Problème de stabilité linéaire et prévision de la transition dans des configurations tridimensionnelles, incompressibles et compressibles , 1992 .

[18]  Jürgen Kompenhans,et al.  Advanced Measurement Techniques for High Reynolds Number Testing in Cryogenic Wind Tunnels , 2010 .