Modeling and Simulation of Propeller Propulsion Model Using Wind Tunnel

Abstract

Accurate investigation of UAV propulsion model plays a very important role in developing a high fidelity complete nonlinear simulation model for UAVs. The present paper focuses on the investigation of an accurate propulsion model used in small propeller-driven UAV. First, both propeller static and dynamic characteristics are measured. Then, the engine model is identified based on experimental measurements of the engine input and output signals. Finally, the complete propulsion model is developed. Using a low speed wind tunnel, a test rig is designed and built to measure static and dynamic performance characteristics of the propeller used in the UAV. Also, it is used to measure engine input and output signals. A sting balance measures the thrust and torque. A magnetic rpm sensor measures propeller rpm and the flight data recorder measures engine throttle position. The test results are then used to find thrust, torque and power coefficients in addition to propeller efficiency. During the tests, dynamic characteristics are obtained by changing either throttle position or wind tunnel airspeed while keeping the other one constant. Both ways are used to allow covering the whole range of advance ratio until reaching the braking and windmill modes. The static characteristics are obtained over a large range of propeller rotational speeds (rpm). The results show good agreement with published data. Engine and servomotor dynamic model is then identified and the complete propulsion model is developed and validated with a very good agreement between simulation and measured data. In order to test and validate the resultant propulsion model, it is integrated into a complete six-DoFUAV simulation model. The simulation results are compared with flight test results for the UAV. This check insists on the quality of the developed propulsion simulation model. Nomenclature C P = Propeller power coefficient. C q = Propeller torque coefficient. C T = Propeller thrust coefficient. D = Diameter of propeller in meter. J = Advance ratio. n = Propeller rotational speed measured in revolutions per second. P = Propeller power. s P = Static pressure. T P = Total pressure. Q = Propeller torque moment. R = Specific gas constant. T = Propeller thrust force.  = Density of air.  = Propeller efficiency.

Simulation of tilt-rotor UAV flight dynamics in horizontal flight

“…In steady-level horizontal, the trim data presented in table 3 are obtained using the graphical trim diagram [20] that presented in figure 10 where the initial state vector and control inputs at the reference steady state are summarized Table 4 . Figure 11 presents a 50 seconds time history for the trim control inputs and the UAV response as well as the 3D trajectory of the UAV.…”

“…To describe the airplane motion, the nonlinear differential equations[13] represent the force, moment, attitude, and trajectory equations in vector form are given as per [Equations(1 -5)]. To avoid the problem of singularity, the attitude equation is presented in quaternion instead of Euler representation.…”