ARTURO (Active contRol of Turbulence for sUstainable aiRcraft propulsiOn) is a 4-years spanish national project (117k€ budget). The main objective is the identification of suitable flow sensing and active control strategies for heat transfer and noise control in turbulent flows of relevance for aero engines.
Turbulent flows are relevant in most industrial and aeronautical thermo-fluid-dynamic applications. Turbulence is characterized by chaotic changes of pressure and flow velocity, in contrast to what occurs with a laminar flow, where a fluid flows in parallel layers. Turbulent flows are responsible for the majority of mass, energy and momentum transport (from the transport of oxygen in the atmosphere to climate comfort in a room, see for example Holmes et al. 2012). For this reason, turbulence has received a very relevant scientific and technological interest in recent years by researchers in different disciplines, mainly engineers (especially in the field aeronautics), physicists and mathematicians (see, for example, the monograph published by Pope, 2000). Understanding the dynamics of these flows is of paramount importance to improve the performance of countless devices and processes in terms of reduction of energy consumption and environmental impact, as well as in terms of functionality.
When talking about aero-engines thermo-fluid-dynamics, turbulence plays a key role in several critical tasks, including mixing and scalar transport in the burner, heat transfer in the turbine and aero-acoustic noise generation and propagation (Kerrebrock, 1992). The understanding and control of these processes is of fundamental importance for a sustainable aeronautical propulsion. The capability of providing high-performance cooling to the turbine blades is needed to obtain high flow temperature in the turbine, which are necessary to obtain high values of thrust per unit of core mass flow rate and high thermodynamic efficiencies (resulting in reduced fuel consumptions and pollutant emissions). On the other side, controlling noise generation and propagation in the jets issued from modern engines is necessary to reduce the acoustic contamination of near-airport neighborhoods, allowing for a more efficient airport usage with a direct impact also on pollutant emissions (ACI Europe, 2018).
Objectives and roadmap
The main goal of ARTURO is is the identification of suitable flow sensing and active control strategies for heat transfer and noise control in turbulent flows of relevance for aero engines. This long-term goal requires reaching three main objectives:
- Development of pattern-recognition tools for the identification of relevant features in boundary-layer heat transfer and jet aeroacoustic problem;
- Identification of suitable flow sensing tools for these relevant flow patterns;
- The selection of control devices with sufficient control authority.
The methodology of ARTURO builds onto four pillars:
- Design of machine-learning algorithms for pattern identification and sensing.
- Design of experimental facility for active flow control in turbulent boundary layer.
- Design of jet-noise experimental facility with flow control.
- Applications of machine-learning methods to flow-control experiments.