High Fidelity Deposition Experiments in Gas Turbine Hot Section Components
Abstract
The ingestion of fine particulate in gas turbines is an issue of increasing importance in the 21st century due to two competing trends: (1) in pursuit of higher efficiency, engine manufacturers are increasing peak temperatures well above the softening temperature of airborne particles and (2) air quality in currently active military theaters (Far East, Middle East, and Africa) is very poor. The confluence of these two trends has led to reduced aircraft availability due to unscheduled maintenance and even aircraft/personnel loss due to in-flight engine failure. Particles that make it into the turbine flowpath can become molten and create deposits that clog cooling paths and restrict critical nozzle guide vane choke area resulting in reduced massflow and compressor surge. Due to the cost of diagnosing and correcting this problem with full-scale engine testing, there has been growing interest in the ability to model particle entrainment, rebound, and deposition computationally. Computational models must be grounded with a solid physical understanding of the relevant phenomena in order to be useful over a wide range of operating conditions and engine types. In practice, this physical understanding comes from careful experimental campaigns that isolate individual mechanisms and provide a means to validate CFD models. While significant progress has been made with predicting particle entrainment (trajectories) and rebound, two critical areas of study are lacking in experimental data, namely: (1) the coupling of deposition with erosion of deposits that occurs simultaneously (and synergistically), particularly in cooling passages and (2) the role of dust mineral composition in dictating deposition rates and morphology. A third essential thrust of the present research proposal is to remedy the dearth of high fidelity deposition experiments to provide validation-quality experimental data to deposition CFD modelers. The goal of the proposed research is to acquire detailed experimental data documenting these deposition phenomena that are unique to the high temperature, high pressure environment of the aero-engine hot section. The experiments will be conducted using several unique, state-of-the-art deposition facilities located at the Aerospace Research Center at OSU. The first test facility is capable of deposition testing of internal turbine cooling components at pressures up to 21atm. The second test facility provides a hot gas stream, seeded with fine particulate, to impact a cooled target specimen at gas temperatures approaching 1800K. A third test facility is the Turbine Reacting Flow Rig (TuRFR) that allows deposition testing to be conducted with cooled production nozzle guide vanes. The final facility is an Impingement Deposition Facility that allows us to replicate the flow condition of an impingement cooling architecture at a higher throughput than the other facilities. The experimental effort will be coupled with a physics-based modeling effort to incorporate the results into a predictive capability. This enhanced deposition model could then open the door to deposition mitigation strategies as well as innovative cooling technologies that enhance efficiency while not sacrificing operability. This proposal constitutes a comprehensive study to provide the aero-engine community with the relevant data and modeling necessary to meet the US Navy’s need for high engine availability and operability in hazardous particle laden
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 01, 2022
- Source ID
- N000142212238
Entities
People
- Jeffrey Bons
Organizations
- Office of Naval Research
- Ohio State University
- United States Navy