Periodic Reporting for period 2 - ASTORIA (Advanced Steady and unsTeady distORtion sImulAtor)
Periodo di rendicontazione: 2021-04-01 al 2022-09-30
Integrated engine/airframe configurations are the leading concept for the forthcoming highly efficient aircraft designs. Such future architectures will be subjected to even much higher levels of distortion at the fan inlet than the current configurations. Inlet total pressure and swirl distortions induce off-design operative conditions on the low pressure compression system, and can as a consequence decrease blading performance, cause varying blade loads resulting in high cycle fatigue and reduced blade life, and last but not least dramatically affect the operational stability margin of the engine. In order to test a priori for these incompatibilities, distortion generation devices have been used to recreate total pressure profiles in a lab or test cell environment. The design of total pressure distortion devices, typically under the form of wire screens, has been an important topic in research for many years. Previously based upon the assembly of several layers of wire screens of different mesh size, the advent of rapid prototyping techniques has allowed for much higher flexibility, and truly tailored design. The full exploitation of this flexibility calls for radically new design methodologies.
The objective of ASTORIA is the development of a set of numerical and experimental tools and associated methodologies allowing sound and reliable parametric studies aiming at replicating and understanding the impact of a wide variety of distortion patterns:
- configurations with boundary layer ingestion (more or less buried)
- vortex with variable location and/or swirl intensity
- a combination of a vortex and a typical flow pattern met during cross-wind operation (mainly total pressure)
The main targets within ASTORIA are:
1. The development of a unique methodology for the design of optimized tailored multicomponent distortion simulator devices able to provide the required combined total pressure and swirl steady pattern at a specific distance from the generator.
2. To provide a proof of concept for the design of unsteady patterns distortion simulators.
3. To validate steady and unsteady patterns design methodologies through extensive experimental testing in precisely controlled conditions.
4. To implement the validated methodology within a highly modular and flexible software tool set.
The objective of ASTORIA is the development of a set of numerical and experimental tools and associated methodologies allowing sound and reliable parametric studies aiming at replicating and understanding the impact of a wide variety of distortion patterns:
- configurations with boundary layer ingestion (more or less buried)
- vortex with variable location and/or swirl intensity
- a combination of a vortex and a typical flow pattern met during cross-wind operation (mainly total pressure)
The main targets within ASTORIA are:
1. The development of a unique methodology for the design of optimized tailored multicomponent distortion simulator devices able to provide the required combined total pressure and swirl steady pattern at a specific distance from the generator.
2. To provide a proof of concept for the design of unsteady patterns distortion simulators.
3. To validate steady and unsteady patterns design methodologies through extensive experimental testing in precisely controlled conditions.
4. To implement the validated methodology within a highly modular and flexible software tool set.
Review of the design methodology:
Literature survey and its analysis - revisiting the global design approach of the proposal. The initial choices are essentially confirmed, but an update of the work plan is proposed in order to focus more effort into the development and validation of the advanced total pressure distortion screen model, as this will be a critical brick of the CFD-based surrogate-assisted design loop. The methodology to be implemented for the two preliminary design tools has been detailed, along with an associated validation proposal based on a selection of canonical use cases. The fine-grained design strategy for the steady combined swirl and total pressure ratio devices has been developed as well as a first tentative design specification, building upon a detailed review of distortion indices and descriptors. Coherently with the selection of descriptors set, the proposed instrumentation has been detailed and first simulations of the test section have been also realised.
Wind tunnel feasibility analysis:
Reporting on the preliminary design of the test section and its services. The adopted methodology has been outlined together with the adopted solution or the possible ways forward for the advance design of the facility. The conclusions in this feasibility analysis have been supported by low-order methods as well as CFD computations.
Development of the design methodology and preliminary design tools:
A first version of the preliminary design tool, as well as a detailed documentation, has been delivered for the design of the advanced pressure distortion screen and swirl vane assembly. The documentation describes in detail the inputs and outputs for the various bricks that form the architecture of each design tool. CFD validation has been performed on the selected canonical cases. The design methodology has been further developed by realising the combined distortion devices design in the global surrogate-based optimisation loop.
Steady test campaign:
The test facility has been designed and commissioned to prepare the steady test campaign. The developed design method for the combined pressure and swirl distortion screens has been applied to design the screens that replicate realistic distortion patterns. These screens, as well as the canonical test case screens, have been manufactured and analysed, and are now ready to be tested.
Literature survey and its analysis - revisiting the global design approach of the proposal. The initial choices are essentially confirmed, but an update of the work plan is proposed in order to focus more effort into the development and validation of the advanced total pressure distortion screen model, as this will be a critical brick of the CFD-based surrogate-assisted design loop. The methodology to be implemented for the two preliminary design tools has been detailed, along with an associated validation proposal based on a selection of canonical use cases. The fine-grained design strategy for the steady combined swirl and total pressure ratio devices has been developed as well as a first tentative design specification, building upon a detailed review of distortion indices and descriptors. Coherently with the selection of descriptors set, the proposed instrumentation has been detailed and first simulations of the test section have been also realised.
Wind tunnel feasibility analysis:
Reporting on the preliminary design of the test section and its services. The adopted methodology has been outlined together with the adopted solution or the possible ways forward for the advance design of the facility. The conclusions in this feasibility analysis have been supported by low-order methods as well as CFD computations.
Development of the design methodology and preliminary design tools:
A first version of the preliminary design tool, as well as a detailed documentation, has been delivered for the design of the advanced pressure distortion screen and swirl vane assembly. The documentation describes in detail the inputs and outputs for the various bricks that form the architecture of each design tool. CFD validation has been performed on the selected canonical cases. The design methodology has been further developed by realising the combined distortion devices design in the global surrogate-based optimisation loop.
Steady test campaign:
The test facility has been designed and commissioned to prepare the steady test campaign. The developed design method for the combined pressure and swirl distortion screens has been applied to design the screens that replicate realistic distortion patterns. These screens, as well as the canonical test case screens, have been manufactured and analysed, and are now ready to be tested.
An accurate knowledge of interactions between embedded engines and inlet/airframe-generated non-uniform flow profiles is essential for the successful robust design of integrated engine systems. In the absence of direct-connect experimentation, flow distortion patterns must be simulated by generating the non-uniformities with flow conditioning devices. The focus of ASTORIA is set on simulating an arbitrarily-complex combined total pressure and swirl distortion.
The experimental test campaign is now ongoing. By using the combination of well-established probe measurements and state-of-the-art PIV measurements, a detailed analysis of the flow will be possible. Supported by complementary CFD computations under the specific testing conditions, this will allow to evaluate the capabilities of the separate and combined distortion devices, and to further improve the design methodology. In parallel, additional collaborative research activities are being prepared to further mature the impact of the ASTORIA.
The experimental test campaign is now ongoing. By using the combination of well-established probe measurements and state-of-the-art PIV measurements, a detailed analysis of the flow will be possible. Supported by complementary CFD computations under the specific testing conditions, this will allow to evaluate the capabilities of the separate and combined distortion devices, and to further improve the design methodology. In parallel, additional collaborative research activities are being prepared to further mature the impact of the ASTORIA.