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Point performance constraints for power sizing (SL: sea-level; HH: high, hot; INOP: inoperative; HOGE: hover out of ground effect, í µí± í µí± : design cruise speed), í µí± í µí±¡ ℎ : VFM-FFM threshold speed)
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... at specified nominal and off-nominal scenarios to determine the constraining flight conditions that size propulsion system architecture components. The flight conditions that were considered are summarized in Table 3. The cruise speed í µí± í µí° ¶ considered for power sizing was varied from 260-350 KTAS. ...Similar publications
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Citations
... The aero-propulsive modeling approach for this configuration has been described in greater detail in Kunwar et al. [54]. It uses an embedded strip-theory based approach for lifting surfaces and a look-up table approach for the remainder of the geometry. ...
This study presents an attainable moment subset-based approach to integrate flight dynamics and control requirements in the conceptual design of a multi-tiltrotor urban air mobility vehicle featuring turbo-electric propulsion system architecture. The goal of this work is to ensure that the control effectors are sufficiently sized to meet the maneuverability requirements in vertical flight mode operations. Off-design cases such as propulsor failure are included when evaluating the maneuver requirements to size the control effectors based on the most constraining scenario. At a given flight condition, the vehicle was trimmed, and all the control effectors were perturbed within the minimum and maximum bounds to evaluate the corresponding accelerations that the vehicle can generate using the non-linear force and moment model. This was used to generate an AMS-hull and it was compared to the required moment subset based on the attitude change requirements defined in ADS-33E-PRF for hover and low speed flight conditions. The propulsor motors were then sized to meet level-1 moderate agility requirements for nominal flight conditions and limited agility requirements for propulsor failure cases. Similarly, the effect of integrating maneuverability requirements on overall vehicle weight buildup was compared to the baseline vehicle which was sized for the same design mission but did not incorporate any maneuverability constraints during sizing. It was found that the roll acceleration requirement in hover with outboard propulsor inoperative sized the propulsor motors. Similarly, the increase in propulsion system weight was found to be most dominating when the sizing results were compared with the baseline vehicle.
... TW-02 Pangolin[100] modified TECS flight control system architecture Control surface mappings are defined by the normalized input scaled by the maximum allowable deflection angle. The resulting control surface deflections are calculated as ...
... The aero-propulsive modeling approach for this configuration has been described in greater detail in Kunwar et al. [45]. It uses an embedded strip-theory based approach for lifting surfaces, a blade element momentum theory (BEMT)-based propulsor performance model, and a look-up table approach for the remainder of the geometry. ...
... Optimization studies on hybrid-electric (HE) aircraft focused mainly on optimizing the power split, minimizing energy used, energy cost, carbon dioxide emission, and several aero-propulsive geometric variables [32][33][34][35][36][37][38][39]. The previous study by the authors focused system sizing for the TW-02 Pangolin, building upon the prior works in [40,41,48]. To facilitate subsystems integration and multi-objective optimization in our study, PEACE was used. ...
... The general arrangement of the Tilt-Wing (TW) vehicle "TW-02 Pangolin", studied in [48], is shown in Figure 4. The tilting wing has six propulsors, three on each wing. ...
... The aero-propulsive model uses an embedded strip-theory based approach for lifting surfaces and blade element momentum theory (BEMT)-based propeller performance model. The lift, drag, and pitching moments ( , , and, ) were generated for each lifting surface using a low fidelity empirical model [48]. The sectional aerodynamics of each strip are queried using the operating AOA, which are computed by subtracting the downwash angle from the incidence angle of the airfoil to free-stream flow. ...
The ongoing development of numerous novel vertical takeoff and landing configurations necessitates flight control system design that enables the Simplified Vehicle Operations paradigm. This paper shows flight test results for one subscale lift-plus-cruise and one tilt-wing configuration employing such a flight control system architecture. Pilot inceptor inputs are used to synthesize trajectory commands that are processed by a full-envelope trajectory control system that generates propulsor thrust commands, a wing angle command, and attitude and rate commands for linear quadratic integral and explicit model-following inner-loop control systems. Commonalities and differences in the flight control implementation for the two configurations are highlighted. Results are shown for both configurations subject in manually piloted flights. The flight test results demonstrate that the flight control system designs allow a minimally trained operator to operate the two flight test vehicles safely and proficiently.
