Explanation of the work carried per WP
Work Package 1: Design and manufacturing of the modified NICETRIP powered components.
A key aspect of the project was to identify the optimal empennage configuration which needs to be effective in stabilizing and controlling the NGCTR both in forward flight and in transition between hover and airplane mode. Two tails were designed and manufactured, to fit into the existing NICETRIP model. In order to preserve geometric similarity between the model and the full-scale prototype, with particular focus on the rotor stream tube/tail interaction, a new set of composite rotor blades was manufactured.
Work package 2: Wind tunnel test preparations of the modified NICETRIP powered model.
All model components were manufactured according plan. All functional checks of instrumentation, model controls, load calibration checks and the GVT were conducted and the model was ready to enter the tunnel end of May 2019.
Work package 3: Wind tunnel test with the modified full span NICETRIP powered model.
The subsonic wind tunnel test was performed in DNW-LLF, the Netherlands. The test matrix primarily covered the low speed range of the flight envelope, from helicopter mode through conversion to aircraft mode. Parametric variation of model component settings were made, such as: “fuselage” incidence and side-slip, outer wing and nacelle tilt angles, control surface settings and rotor operating points. The test program concentrated on aerodynamic interactions and tail effectiveness of both T-tail and V-tail.
The actual test had to be split in two separate entries due to unforeseen circumstances: the 1st from 3-19/6/2019, the 2nd from 28/11-10/12/2019, adding up to over 15 days of tunnel occupation.
Work package 4: Wind tunnel data analysis.
Due to the unforeseen circumstances the data delivery was done in two steps. The project partners used the period between the two test entries to already concentrate on checking and correcting the available data from the first entry. In fact the majority of procedures for final data production were investigated and finalized even before the second entry.
Due to the necessity as input for other projects at Leonardo Helicopters, processing of tail data was already in full swing after the first entry. In order to prevent duplication of processing it was decided
* to focus on further investigations of the tail balance. Tail balance results during NEXTTRIP were suspicious and reliable measurements within HIGHTRIP are of major importance,
* to report the efforts put in FLIGHTLAB modelling of rotor wake and impingement on the tails that were initiated already at the start of the project.
* to perform a limited study of stability behavior.
Work package 5: Empennage optimization to enhance the stability behavior of NGCTR.
In a 4-step approach a multi-criteria multi-constrained Aerodynamic Optimization of 3D finlets was carried out, which resulted in an optimal shape increasing longitudinal and latero-directional stability of the V-tail, while at the same time minimizing drag and lowering rolling moment at the tail root.
In parallel, a parametric study on V-tail/fuselage connection was carried out, analyzing both a fillet and a fairing configuration.
Finally, a DoE-based parametric study was carried out on the V-tail planform, providing dependencies of the aerodynamic coefficients from root offset, dihedral angle and aspect ratio.
Work package 6: Management, dissemination and exploitation.
As part of the project management, a Project Management Plan was issues as were a Dissemination Action Plan and an Exploitation Plan. In due course of the project dissemination and exploitation actions were initiated.
