Periodic Reporting for period 2 - TRUflow (Thrust Reverser Unit flow visualization)
Okres sprawozdawczy: 2020-11-01 do 2022-10-31
In 2001, the Advisory Council for Aviation Research and Innovation in Europe (ACARE) published the much referenced ‘Vision’ for 2020 which set targets of 50% reductions in fuel-burn and perceived noise, and 80% in landing/take-off NOx emissions, relative to year-2000 aircraft. This ambitious target aimed to promote a secure European global leadership in the aviation market while simultaneously responding to societal needs. ‘FlightPath 2050’, further expanded these targets to 75% fuel reduction, 65% perceived noise and 90% landing/take-off NOx emissions by 2050. The massive challenges embodied in these documents are far from an isolated issue for the European aviation community – for instance, similar initiatives proposed by NASA for the ‘N+2’ (service-entry 2025) and ‘N+3’ (service-entry 2030–2035) generations of aircraft demonstrate the heightened global awareness of the issues. These challenges have stimulated significant activity in wide ranging future technologies, from operation and airframe to advanced materials and control systems.
The Thrust Reverser Unit flow visualization (TRUflow) project main objectives are to design and validate novel flow diagnostic/visualisation technologies and implement them in representative isolated and installed test rigs of TRUs. A static isolated demonstrator with an ejector and an isolated/installed test rig with a fan will be built during the TRUflow project. The minimum aim of the project is to take all selected technical approaches to TRL5 or higher.
To summarize the objectives of TRUflow project are:
a. Development of measurement technique for the visualization and evaluation of reverse flow interactions with fan in a static demonstrator of an isolated configuration with TRU
b. Apply the novel techniques in a wind tunnel test of the installed configuration with TRU
c. Numerically evaluate the isolated and installed configuration with TRU
d. Generate a surrogate model for the TRU cascades and implement it into a CFD solver
In order to fulfil these objectives, the work has been divided into four Work Packages (WP):
WP1. Design and manufacture of a model suitable for static demonstration and wind-tunnel tests incorporating the optical methods of WP2
WP2. Develop optical techniques to aid visualisation of the flow
WP3. Perform static demonstration (at ARA) and wind-tunnel tests (at RUAG)
WP4. Employ Computational Fluid Dynamics (CFD) simulations of both the static demonstration and the wind-tunnel test in order to develop novel boundary conditions which will aid the efficient design of TRUs in future.
The Thrust Reverser Unit flow visualization (TRUflow) project main objectives are to design and validate novel flow diagnostic/visualisation technologies and implement them in representative isolated and installed test rigs of TRUs. A static isolated demonstrator with an ejector and an isolated/installed test rig with a fan will be built during the TRUflow project. The minimum aim of the project is to take all selected technical approaches to TRL5 or higher.
To summarize the objectives of TRUflow project are:
a. Development of measurement technique for the visualization and evaluation of reverse flow interactions with fan in a static demonstrator of an isolated configuration with TRU
b. Apply the novel techniques in a wind tunnel test of the installed configuration with TRU
c. Numerically evaluate the isolated and installed configuration with TRU
d. Generate a surrogate model for the TRU cascades and implement it into a CFD solver
In order to fulfil these objectives, the work has been divided into four Work Packages (WP):
WP1. Design and manufacture of a model suitable for static demonstration and wind-tunnel tests incorporating the optical methods of WP2
WP2. Develop optical techniques to aid visualisation of the flow
WP3. Perform static demonstration (at ARA) and wind-tunnel tests (at RUAG)
WP4. Employ Computational Fluid Dynamics (CFD) simulations of both the static demonstration and the wind-tunnel test in order to develop novel boundary conditions which will aid the efficient design of TRUs in future.
The following work has been completed on each of the work packages:
WP1. The vast majority (95%) of the design and manufacture work of the model has been completed at ARA. This includes a complete static demonstrator model as well as the fan and many other systems to convert the demonstrator into the final wind-tunnel model. Motor design and manufacture (at RUAG) is progressing well with a full twin rotor motor now running at 30,000rpm.
WP2. A complete review of the state-of-the-art approaches to flow visualisation was performed (WP2.1) before the COVID-19 pandemic. An initial investigation landed on the use of Particle Image Velocimetry (PIV) and Pressure Sensitive Paint (PSP). These approaches were evaluated further and developed according to the exact specification requirements (velocity ranges, pressure ranges, geometric restrictions etc.) A further work sub-package (WP2.1) is ongoing to procure and begin prototyping these flow diagnostic techniques. Many issues regarding positioning of cameras, illumination and electronic control of the systems have been resolved or are in the process of being resolved.
WP3. Due to COVID-19, no testing has been completed as yet but the static demonstrator test is currently planned for 2021 Q2 with the wind-tunnel test in 2021 Q3.
WP4. Initial CFD simulations of the static demonstrator set-up have been completed and are due for publishing at AIAA SciTech in January 2021. These initial simulations have allowed the selection of appropriate turbulence models which will allow an accurate prediction of the effectiveness of the TRU assembly. Actuator disk and chimera mesh methods for simulating the full, fan-driven wind-tunnel model assembly is ongoing.
WP1. The vast majority (95%) of the design and manufacture work of the model has been completed at ARA. This includes a complete static demonstrator model as well as the fan and many other systems to convert the demonstrator into the final wind-tunnel model. Motor design and manufacture (at RUAG) is progressing well with a full twin rotor motor now running at 30,000rpm.
WP2. A complete review of the state-of-the-art approaches to flow visualisation was performed (WP2.1) before the COVID-19 pandemic. An initial investigation landed on the use of Particle Image Velocimetry (PIV) and Pressure Sensitive Paint (PSP). These approaches were evaluated further and developed according to the exact specification requirements (velocity ranges, pressure ranges, geometric restrictions etc.) A further work sub-package (WP2.1) is ongoing to procure and begin prototyping these flow diagnostic techniques. Many issues regarding positioning of cameras, illumination and electronic control of the systems have been resolved or are in the process of being resolved.
WP3. Due to COVID-19, no testing has been completed as yet but the static demonstrator test is currently planned for 2021 Q2 with the wind-tunnel test in 2021 Q3.
WP4. Initial CFD simulations of the static demonstrator set-up have been completed and are due for publishing at AIAA SciTech in January 2021. These initial simulations have allowed the selection of appropriate turbulence models which will allow an accurate prediction of the effectiveness of the TRU assembly. Actuator disk and chimera mesh methods for simulating the full, fan-driven wind-tunnel model assembly is ongoing.
State of the Art and Expected Results
There are three main aspects of the TRUflow project which are innovative in nature and these are now discussed in turn.
1) Flow visualization ambition
The project partners aim to build a sensor package which is robust and reliable and can be installed in compact spaces to measure internal flows. The importance of field measurements in such tight spaces cannot be understated to the wider aerospace community. Examples such as TRU, or the flow behind high-lift devices, remain some of the last challenges in CFD validation. Current flow diagnostic technology is limited to laboratory-scale measurements or, for example PIV, large-scale freestream measurements. The development of miniaturised sensor packages will also enable installation on real test vehicles such as flight demonstrators or road vehicle demonstrators.
2) New cascade TRU boundary condition
Within the previous CS2 ReLOAD project, ARA used VFM to merge CFD and WTT data, so advancing the TRL of using VFM in this way. TRUflow will mature the use of VFM as a CFD/WTT data fusion tool to generate data for an innovative TRU cascade boundary condition. A successful demonstration of the use of VFM as a data fusion tool to merge CFD and WTT datasets in order to generate a new boundary condition has the potential to reap significant benefits downstream of this project. The new boundary condition has the prospect to reduce the cost and time of the design of the TRU cascades and hence to increase the TRL of this approach. The consortium has not seen this attempted before. It also important to notice that the experimental CFD data will form a unique database for methods and tools validation and verifications. Allowing the TM, the consortium members to increase the TRL of their toolset.
3) New wind tunnel testing capabilities
The development of a new higher power hydraulic motor powering a new turbofan simulator will expand and demonstrate extended testing capabilities of the wind tunnel. New aircraft architectures often present a higher level of integration of the power system into the airframe than current aircraft configurations. Interference between the airframe on the power plant thus becomes more important. The hardware, but also the gained know-how in TRUflow, will allow RUAG to better respond to future requirements for wind tunnel testing of powered models of future aircraft concepts.
Impact
The focus of this project is to develop and prove the innovative measurement technique required for the testing of short and slim aero-engine nacelle fan with TRU. A secondary focus is also the development of a surrogate model for the design of TRU cascades.
In terms of the impact and benefit to the competitiveness of Europe and associated countries, it is envisaged that the work will be of significance to stakeholders of aero-engine, aircraft as well as wider industrial and academic parties through exploitation of the generic aspects of experimental methods, CFD validation, and improvements to aerodynamic design of TRU cascades systems.
There are three main aspects of the TRUflow project which are innovative in nature and these are now discussed in turn.
1) Flow visualization ambition
The project partners aim to build a sensor package which is robust and reliable and can be installed in compact spaces to measure internal flows. The importance of field measurements in such tight spaces cannot be understated to the wider aerospace community. Examples such as TRU, or the flow behind high-lift devices, remain some of the last challenges in CFD validation. Current flow diagnostic technology is limited to laboratory-scale measurements or, for example PIV, large-scale freestream measurements. The development of miniaturised sensor packages will also enable installation on real test vehicles such as flight demonstrators or road vehicle demonstrators.
2) New cascade TRU boundary condition
Within the previous CS2 ReLOAD project, ARA used VFM to merge CFD and WTT data, so advancing the TRL of using VFM in this way. TRUflow will mature the use of VFM as a CFD/WTT data fusion tool to generate data for an innovative TRU cascade boundary condition. A successful demonstration of the use of VFM as a data fusion tool to merge CFD and WTT datasets in order to generate a new boundary condition has the potential to reap significant benefits downstream of this project. The new boundary condition has the prospect to reduce the cost and time of the design of the TRU cascades and hence to increase the TRL of this approach. The consortium has not seen this attempted before. It also important to notice that the experimental CFD data will form a unique database for methods and tools validation and verifications. Allowing the TM, the consortium members to increase the TRL of their toolset.
3) New wind tunnel testing capabilities
The development of a new higher power hydraulic motor powering a new turbofan simulator will expand and demonstrate extended testing capabilities of the wind tunnel. New aircraft architectures often present a higher level of integration of the power system into the airframe than current aircraft configurations. Interference between the airframe on the power plant thus becomes more important. The hardware, but also the gained know-how in TRUflow, will allow RUAG to better respond to future requirements for wind tunnel testing of powered models of future aircraft concepts.
Impact
The focus of this project is to develop and prove the innovative measurement technique required for the testing of short and slim aero-engine nacelle fan with TRU. A secondary focus is also the development of a surrogate model for the design of TRU cascades.
In terms of the impact and benefit to the competitiveness of Europe and associated countries, it is envisaged that the work will be of significance to stakeholders of aero-engine, aircraft as well as wider industrial and academic parties through exploitation of the generic aspects of experimental methods, CFD validation, and improvements to aerodynamic design of TRU cascades systems.