Periodic Reporting for period 2 - InVIGO (INtake Vortex Ingestion on Ground Operations)
Reporting period: 2021-01-01 to 2022-01-31
As new fuel-efficient bypass engines are becoming increasingly wider in diameter, the distance between the (underwing mounted) engine and runway decreases. Reduced ground clearance can boost ground interactions during taxi and take-off phases, and ground vortices can appear, especially when there are crosswinds.These ground vortices go into the engine intake and can damage fan blades due to foreign object ingestion, dynamic loading and structural vibration. It is therefore crucial to be able to predict the characteristics of these ground vortices during early design phase, to improve engine's fan blades for safety and performance issues.
During early design phases, only reduced instrumentation can be used, whereas in-depth measurements would be required for ground vortex characterization. Therefore, InVIGO project's main objective is to build a predictive model to be used during early design phases with such reduced instrumentation. This model will use machine learning algorithms that will be trained with database coming from wind tunnel testings and numerical simulations performed within Invigo. Both reduced and detailed measurements will be carried out to build the training database. This main objective is therefore related to two essential steps. First is carrying out two wind tunnel campaigns in CSTB facility with a engine nacelle model and many instruments (pressure probes and rakes, Stereo-PIV, PTV, ...). Second is performing a hundred of numerical simulations (CFD) to complement wind tunnel measurements and addressing topics that cannot be dealt with experimentally (scale effect for example).
At the end of the project, the conclusions are the following. All the technical objectives were reached. A large number of simulation and wind tunnel tests were carried out and generated a very large database. Many predictive model were built and trained and the best one gave good results regarding the prediction of average vortex characteristics. This model was embedded within an interface to be reused on new vortex configurations. The impact of the project is also in line with what was planned at the beginning. Altran and CSTB presented 6 papers in scientific conferences and there is one paper published in a journal. The project outcomes will help in achieving Clean Sky 2 objectives regarding pollution, safety and costs, thanks to new engines more optimized. The EU competitiveness will also rise thanks to the new capabilities of the Jules Verne wind tunnel of CSTB, which also gained key expertise on such European projects. In parallel, Altran reinforced its expertise in simulation and data science and its ability to coordinate and manage such consortium. Last but not the least, the Topic Leader will eventually use all the content generated to best design the next generation of engine, whether classical ducted engines such as the UHBR, or newer technologies such as the unducted RISE project. Discussions and common actions are planned far beyond the end of the project between all takeholders.
During early design phases, only reduced instrumentation can be used, whereas in-depth measurements would be required for ground vortex characterization. Therefore, InVIGO project's main objective is to build a predictive model to be used during early design phases with such reduced instrumentation. This model will use machine learning algorithms that will be trained with database coming from wind tunnel testings and numerical simulations performed within Invigo. Both reduced and detailed measurements will be carried out to build the training database. This main objective is therefore related to two essential steps. First is carrying out two wind tunnel campaigns in CSTB facility with a engine nacelle model and many instruments (pressure probes and rakes, Stereo-PIV, PTV, ...). Second is performing a hundred of numerical simulations (CFD) to complement wind tunnel measurements and addressing topics that cannot be dealt with experimentally (scale effect for example).
At the end of the project, the conclusions are the following. All the technical objectives were reached. A large number of simulation and wind tunnel tests were carried out and generated a very large database. Many predictive model were built and trained and the best one gave good results regarding the prediction of average vortex characteristics. This model was embedded within an interface to be reused on new vortex configurations. The impact of the project is also in line with what was planned at the beginning. Altran and CSTB presented 6 papers in scientific conferences and there is one paper published in a journal. The project outcomes will help in achieving Clean Sky 2 objectives regarding pollution, safety and costs, thanks to new engines more optimized. The EU competitiveness will also rise thanks to the new capabilities of the Jules Verne wind tunnel of CSTB, which also gained key expertise on such European projects. In parallel, Altran reinforced its expertise in simulation and data science and its ability to coordinate and manage such consortium. Last but not the least, the Topic Leader will eventually use all the content generated to best design the next generation of engine, whether classical ducted engines such as the UHBR, or newer technologies such as the unducted RISE project. Discussions and common actions are planned far beyond the end of the project between all takeholders.
Nearly 100 configurations were characterized experimentally by CSTB with almost 200 000 PIV images, giving a very large vortex database. Jules Verne Wind tunnel was dedicated to InVIGO during more than 5 weeks in total, with 3 full weeks of data acquisition. More than 100 full simulations were performed by Altran for multiple purposes : wind tunnel data complement, analysis of scale effect, analysis of wind effect. All these simulations needed to be unsteady and were performed with hybrid RANS/LES approach to best capture the real behaviour of the ground vortex. These simulations must be added to all the preliminary simulations performed to set up the methodology. All the data generated was eventually gathered in a database processed with Data Analytics techniques by Altran. Multiple techniques were implemented and tested. The best one finally used MultiLayer Perceptron (neural network) and directly predicted the vortex characteristics. Several models were trained and the best one was embedded in a dedicated tool to allow Safran predicting new ground vortices.
The expertise gained on all technical aspects will be reused by Altran and CSTB to address other aeronautical topics. The consortium has built a strong link with the Topic Leader and will continue to discuss with it on the ground vortex topic. It will follow internship progress at Safran and all this may lead to new contracts or new research projects.
The results of all technical fields were disseminated in several scientific congresses (3AF, NAFEMS, EASN): a total of 3 (+3 right after the project end) congress publications were presented whose one complemented for a publication with peer-review process. Many communication actions were also carried out to enhance the communication and dissemination of the project : web site, leaflet, posters, workshops... The exploitation and dissemination will continue after the project. CSTB will re-use the suction fan for new studies and will tackle new aeronautical studies thanks to their increased expertise in this field. Altran will apply the methodology for CFD simulations on new topics, even out of aeronautical field. The Data science method set up in InVIGO will also be applied to new technical environments. The Topic Leader will also start from all InVIGO results to build new research activities to design more innovative engines for next generation.
The expertise gained on all technical aspects will be reused by Altran and CSTB to address other aeronautical topics. The consortium has built a strong link with the Topic Leader and will continue to discuss with it on the ground vortex topic. It will follow internship progress at Safran and all this may lead to new contracts or new research projects.
The results of all technical fields were disseminated in several scientific congresses (3AF, NAFEMS, EASN): a total of 3 (+3 right after the project end) congress publications were presented whose one complemented for a publication with peer-review process. Many communication actions were also carried out to enhance the communication and dissemination of the project : web site, leaflet, posters, workshops... The exploitation and dissemination will continue after the project. CSTB will re-use the suction fan for new studies and will tackle new aeronautical studies thanks to their increased expertise in this field. Altran will apply the methodology for CFD simulations on new topics, even out of aeronautical field. The Data science method set up in InVIGO will also be applied to new technical environments. The Topic Leader will also start from all InVIGO results to build new research activities to design more innovative engines for next generation.
The database generated is by far the largest regarding ground vortex characteristics. Moreover, InVIGO takes into account the spinner effect which was not generally included in the literature.
The analysis of PIV data showed very new results in terms of vortex position along time and depending on configuration.
The CFD methodology set up allows involving the vortex unsteadiness and getting temporal signals for vortex characteristics. A very good agreement was found between CFD and Wind Tunnel data.
The socio-economic impact of the project will mainly result from more optimized engines : fan blades will be best designed thanks to this deeper knowledge of ground vortex that will become a subject of concern for new engine generations. This will results in safer engines, with less pollution and fuel consumption. This should lead to cheaper and greener travels.
The analysis of PIV data showed very new results in terms of vortex position along time and depending on configuration.
The CFD methodology set up allows involving the vortex unsteadiness and getting temporal signals for vortex characteristics. A very good agreement was found between CFD and Wind Tunnel data.
The socio-economic impact of the project will mainly result from more optimized engines : fan blades will be best designed thanks to this deeper knowledge of ground vortex that will become a subject of concern for new engine generations. This will results in safer engines, with less pollution and fuel consumption. This should lead to cheaper and greener travels.