Reality Check: Design validation methods go into ORBIT
Developing the right technologies for the multi-stage intermediate pressure (IP) turbine for the Very High Bypass Ratio engine concept being developed for the Rolls-Royce UltraFan® engine is essential for ensuring European aero-industry competitiveness and compliance with ACARE targets to reduce CO2, NOx and noise emissions. Clean Sky's ORBIT (Aerodynamic rigs for VHBR IP turbine) project is a very large experimental test campaign covering both aerodynamics and aero-acoustic measurements to validate the design methods associated with the 'middle of the market' engine which heralds a new era in aeronautic engine design, based on innovative architecture.
This project addresses the topic of experimental validation rig testing in order to develop aerodynamic technologies for the multi-stage intermediate pressure (IP) turbine of the Very High Bypass Ratio engine (VHBR). The advancement of multi-stage IP Turbine technologies is an important contributor to Rolls-Royce's UltraFan® which is a VHBR engine concept and aims to contribute significantly to reduce emissions and noise as well. The objective is a 25% fuel-burn reduction relative to the year 2000 baseline, or 10% relative to the 2014 baseline.
Dr. Jean-François Brouckaert, Clean Sky's Engine ITDs Team Leader, adds that "The idea is that there is a gearbox in the engine concept. The IP turbine is running fast, three times higher than a normal LP turbine on a direct drive turbo fan. It is very large experimental test campaign covering both aerodynamics and aero-acoustic measurements to validate their design methods on high-speed turbines".
The project started in January 2017 and runs until the end of December 2020. It aligns with the global objectives of Clean Sky 2, which aim towards achieving the ambitious ACARE goals and the long-term objectives of Flightpath 2050 in respect of reducing CO2, NOx and noise emissions. ORBIT is intended to ensure European competitiveness, with specific relevance to the 'middle of the market' category of aircraft, which not only faces fierce competition from the Americas (both North and South) but also from evolving competitors in Russia and China.
To accomplish this, the project, coordinated by Centro de Tecnologías Aeronáuticas (CTA) – the Miñano, Spain-headquartered aerospace test laboratory which specialises in testing for development and certification of aerospace materials, systems and structures – is working towards delivering individual improvements in sub-system technology developments, to support the overall development of system-level technologies capable of delivering substantial reductions in emissions.
CTA is carrying out all the tasks to permit the experimental validation of relevant aerodynamic technologies such as design, manufacture, assembly, finally testing and post-processing, with four work packages oriented around the testing of innovative geometries to assess the improved losses and reduction in the generated noise. A fifth work package is dedicated to comparison of the former results with relevant reference rig tests, as is an opportunity to integrate new knowledge to support the application of new design innovations.
"European aviation and hence European aviation companies need to be at the forefront of technology to be able to offer the most reliable and efficient products" says Josu Beloki Perurena, Project Manager of the ORBIT project at CTA. "The project targets the environmental and competitiveness challenge of the European aeronautics sector, by addressing the topic of experimental validation rig testing to develop aerodynamic technologies for the multi-stage IP turbine of the UltraFan®".
In terms of testing and demonstrations, Perurena says that “two of the four planned IP Turbine rig tests have been completed. The results have been used to validate aerodynamic and aeroacoustic technologies related to the rear stages of the IP Turbine up to Technology Readiness Level 4 (TRL4). The first rig has been used to study 2D and 3D losses in detail and noise performance of airfoils of the rear stages of the UltraFan® IP Turbine. During later testing, detailed measurements have been obtained to characterize aerodynamic and noise performance of 3D optimized geometry for noise reduction”.
Perurena says that the ORBIT project represents "a significant milestone in the development of the aeronautic engine of the future," which will deliver individual improvements in this new engine’s sub-system technology developments, "positioning Rolls-Royce and its sub-system partners such as ITP Aero [the Spanish engine company that operates as a corporate entity within the Rolls-Royce Group] at the forefront of aeronautic engine technology".
As for the social and environmental benefits, Perurena says that “The UltraFan® will help to deliver European aviation environment requirements, cleaner and quieter to minimize air transport systems’ impact on climate. Once the UltraFan® engine is in operation, it will significantly cut CO2 emissions, NOx emissions, noise pollution and it will minimize turnaround times to meet consumer expectations. It also supports European aviation industry’s global leadership by reinforcing the competitiveness and performance of aviation manufacturing industries".