Main expected results:

Engineering feasibility of noise and vibrations mitigation technologies proven by means of prototype demonstration in operational environment [TS6]

  • Improve design and analysis from dynamic point of view (transient and aeroelastic response)
  • Improvement of landing gear doors manufacturing process (new materials, new design principles)

Progress so far:


Within the scope of defining devices to reduce the vibration levels of the main landing gear door, important steps towards flight test have been achieved.

All CFD calculations have been completed for the baseline configurations covering different parts of the flight (take-off and approach) as well as fully and partly deployed landing gear. Comparisons to flight test data from previous tests show a good agreement to the numerical results. Further insight will be possible, once the flights within AFLoNext have been performed. The CFD and flight test data has been used to develop mitigation devices in the landing gear area. Three sources for the main landing gear door vibrations have been identified: the wake of the nose landing gear, the interaction between the flow and the main landing gear door cavity and the separation on the main landing gear door itself. Based on this knowledge, several devices have been developed and are currently being assessed in terms of practical feasibility and effectiveness.

The GVT on the main landing gear door has been performed and the data is currently being used to update the FEM. The updated FEM will allow a more accurate prediction of the door behavior during flight test as well as the assessment of structural mitigation devices. 

The new monolithic nose landing gear door concept has been frozen. The new door consists of a stiffener panel concept made from monolithic carbonfibre prepreg. 

APRIL 2015

Within the scope of defining devices to reduce the vibration levels of the main landing gear door, the CFD and FEM community have achieved important results. On the CFD side, most of the unsteady calculations have been completed and are currently being analysed, with only a few calculations currently still underway. Simulations have been performed with and without the nose landing gear and also at take-off and approach conditions with different landing gear positions, in order to cover the important conditions during the landing gear cycle. The FE model has been simplified and distributed and the coupling of the already available CFD results with the FE model is currently underway. The next steps will be to complete the CFD runs and the analysis of the results as well as providing the input to the FEM community for coupling.
The definition of the flight test instrumentation has been completed and the preparation of the ground vibration test is currently underway, with the test being scheduled for February this year.
The design and manufacturing concept of the monolithic nose landing gear door has also progressed further. Several concepts of door were studied (by design and/or analysis) to select the most suited concept for final design. At this stage, the main concept is based on a door composed of a lower skin with several longitudinal cells and a second concept with transversal cells.

Fig. : RANS-LES CFD simulation obtained for Nose Landing Gear in Take-Off condition of α=10.5, 180kt, sea level M=0.272. Courtesy of Totalforsvarets Forskningsinstitut (FOI).

JULY 2014

On the CFD side, the aircraft, landing gear, cavity and door geometries have been successfully cleaned-up. Steady computations have been performed by most partners and first unsteady results are also already available. Two landing gear positions have been defined, one fully extended and one with the main landing gear bogey in the vicinity of the inboard main landing gear door. Two flight conditions have been defined, representing a typical landing and take-off case. The unsteady simulations will cover configurations with and without the nose landing gear, in order to determine the influence of the nose landing gear on the main landing gear inboard door vibrations. The first available unsteady results are for the configurations without nose landing gear and show low levels of unsteadiness. This suggests the nose landing gear to have significant contribution to the door vibration.

The FE community has performed first calculations to ensure model conformity over all partners. Close cooperation is ongoing between the CFD and FE community to ensure a smooth transfer of results. The planning of the GVT and FT is succeeding with the FTI being completely defined. The GVT will most likely be performed in January 2015. Several designs for the monolithic nose landing gear door have been assessed and close cooperation with Airbus has been established to ensure a smooth certification of the new door for flight.

Figure - Distribution from a steady RANS simulation performed by the partner Kungliga Tekniska Hoegskolan.


The geometry clean-up to get simpler geometrical shapes and watertight geometries for meshing and CFD calculations is ongoing and almost complete. The meshing approach and number of meshes needed to satisfy the needs of all partners were also discussed and appropriate actions were placed. First numerical results on simplified aircraft geometries have been obtained by Kungliga Tekniska Högskolan and CFS Engineering SA, with the other partners following soon. The following points have been discussed:

  • FE model, which in the meantime, has been distributed.
  • Dependencies between structural modelling and aerodynamical modelling.
  • Flight test requirements, especially the GVT and FTI requirements.
  • Draft FTR which is now available and will be detailed and completed in the next months.
Figure Simulation of the flow field around the main landing gear door of an Airbus A320.