Turboprop engines are known for their high fuel efficiency on short-range missions compared to turbofan engines. A disadvantage of turboprop engines is the noise they produce. The dominant noise source of the turboprop engine is the propeller. The goal of this research is to develop a propeller source noise model which has the future goal to extend already existing noise prediction tools like the VCNS (Virtual Community Noise Simulator). In this research the Helicoidal Surface theory is coupled with two external aerodynamic tools, XFoil and XRotor, for the computation of the harmonic noise sources of the propeller. The developed tool is called the HeliX-tool. The harmonic noise sources that are implemented for the computation of the propeller noise are the steady loading noise and the thickness noise. The HeliX-tool is successfully implemented in Matlab and the tool is validated using literature data and two NLR-tools (one for the propeller aerodynamics and one for the propeller acoustics). From the validation some limitations came to light. For operating conditions that result in high local Mach numbers (>0.7 Mach), the HeliX-tool shows bad agreement with the literature data. For lower local Mach numbers the HeliX-tool shows good agreement with literature data and the NLR-tools. Additional comparisons are made using the HeliX-tool and NLR-tools for operating conditions that are not considered in the literature data. The agreement with the NLR-tools is shown by these comparisons. However, for harmonic numbers higher than 1 the difference between the HeliX-tool and NLR-tools becomes more noticeable as the harmonic decay of the HeliX-tool is larger. More research into the higher harmonic numbers can possibly improve the agreement for the higher harmonic numbers. The ultimate aim of the HeliX-tool is to be able to perform a noise simulation of a propeller. Therefore an auralization of a propeller fly-over is performed. Several propagation effects are taken into account. These are the ground reflection, spherical spreading, atmospheric absorption and the Doppler frequency shift. As a result an audible simulation of a propeller fly-over is obtained. ... Read more

This report is the final report in a series of four reports that deals with the design of an advanced regional aircraft. The first step in the design is to determine the overall configuration of the ARA. By identifying the feasible configurations based on a literature study and performing a trade-o_, the conventional low wing with GTF engines underneath the wings configuration is found to be the optimal configuration for the ARA. After selecting the aircraft configuration, the preliminary subsystem design is initiated. Class I and II weight estimations are performed and a MTOW of 34500kg is determined. The selected wing planform is a two-piece complex sweptback planform with a wing area of 105m2 and a wing span of 30.7m. The thrust will be provided by two PW1217G GTFs with a maximum thrust of 76kN each. For the fuselage design, several configuration options are analysed taking into account structural and aerodynamic considerations. A trade-o_ is performed and the 4 abreast configuration with cargo in the tail is found to be the best choice. The tricycle configuration is chosen for the landing gear. The main gear is positioned 17.1m from the nose, while the nose gear is positioned 3.6m from the nose. The control surfaces comprising ailerons, spoilerons, elevators and rudder, are sized for extreme load cases. For roll control at low speeds outboard ailerons are used and spoilerons are used for roll control at high speeds. The elevators are sized to meet take-o_ and trim requirements. The rudder is sized to counteract the yawing moment with one-engine inoperative. Furthermore, the high-lift devices are sized. It is found that in order to fulfill landing and take-o_ requirements double-slotted Fowler flaps are required... ... Read more