Advancing Prediction Methods for Complex Curvature Nozzle Flows Relevant to Next-Generation Naval Propulsion
Abstract
The purpose of this action is to add FY23 funds for a new start Grant. GRANT13813065. The period of performance will be three (3) years.--Modern and future aircraft systems are trending towards increased airframe-propulsion integration for mission and performance benefits. Advanced propulsion systems require shape transition between circular and non-circular cross-sections and often include complexinternal curvature and three-dimensional flow structures from mixing devices. While engine hot section components such as turbines and nozzles have globally favorable pressure gradients, complex shapes result in local adverse pressure gradients that drive unsteady, three-dimensional transport of mass, momentum, and energy. This has major implications for system performance, particularly the propulsive efficiency due to viscous losses and increased thermal loading on surfaces. The complex momentum and thermal transport canbe extremely challenging to predict computationally, which can result in insufficient cooling in hot section components to mitigatethermal loading at the surfaces. We propose advancing the ability to predict three-dimensional, pressure-gradient-driven flows through a tightly integrated experimental and computational validation effort. The nozzle geometries will be simple, canonical geometries to remain as fundamental reserach, however, input on geometry and operating conditions from supporting partners GE Aerospace and NAVAIR will be incorporated to ensure future Naval relevance.The primary goal of this research is to advance the ability to accurately predict flows with complex curvature relevant to next-generation Navy aircraft nozzles and propulsion systems.} The key goals are:1. Generate an extensive database of validation-quality internal experimental measurements for accelerating flows with shape transition.2. Elucidate relationships between local internal pressure gradients and nozzle performance for canonical geometries.3. Identifyand assess turbulence model errors by minimizing numerical errors through solution adaptive meshing.4. Improve RANS turbulence model formulations for more accurate prediction of accelerating internal flows with shape transition and curvature.This effort will be atightly integrated experimental and computational effort focused on three-dimensional flow with complex curvature and local adversepressure gradients. The experimental model for this research will be a nozzle with optically-accessible internal flow (acceleratingflow) with simple, canonical geometries containing locally favorable and adverse pressure gradients. Computational validation will focus on canonical geometries for isothermal flow followed by an investigation of increasingly complex mixing configurations and thermally striated flows (heated flow with a cold flow layer near a surface). Emphasis will be placed on minimizing discretization and experimental error through rigorous validation efforts to identify shortfalls in the modeling practices and advance the methods for predicting complex flows for next-generation naval propulsion systems. Improved RANS turbulence model formulations will be suitable for integration into any existing CFD software without modifications of the non-linear solver framework. Approved for Public Release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 29, 2023
- Source ID
- N000142312506
Entities
People
- Daniel R. Cuppoletti
Organizations
- Office of Naval Research
- United States Navy
- University of Cincinnati