Modeling Deposition in Turbine Cooling Passages With Temperature-Dependent Adhesion and Mesh Morphing

Abstract

The role of temperature on deposition in gas turbine internal cooling geometries is investigated. Single impingement cones are developed by an oversized (6 mm) impinging jet over a range of temperatures and flow velocities using 0–5 μm Arizona road dust (ARD). Cone size was found to increase with increasing temperature and decrease with increasing velocity. Capture efficiency and cone angle effects are presented, and packing factor (PF) data are used as a metric to determine if the contact area (Acont) for adhesion explains the trends seen with temperature. It is systematically demonstrated that the surface free energy (γ) is likely a first-order function of temperature in internal deposition for the range of temperatures investigated. Candidate physical mechanisms that may cause increased adhesive force at elevated temperatures are identified. Temperature-dependent adhesion is added to the Ohio State University (OSU) deposition model which is then used with a simplified morphing approach to match temperature-induced blockage patterns in a vane leading edge cooling experiment. This process is improved upon using a full mesh morphing routine and matching two of the experimental deposition cones at varied flow temperatures. The added fidelity that mesh morphing affords is demonstrated.