Rotor interacting with a beam noise database as presented in Gojon, Parisot-Dupuis, Mellot, & Jardin. Aeroacoustic radiation of low Reynolds number rotors in interaction with beams. JASA, 2023. Thrust and power coefficients, as well as autopower of acoustic pressure are given. The name gives the operating point, for example, in the files ISAE_2_D10_L20_autopower and ISAE_2_D10_L20_static, D stands for the circular geometry of the cylinder beam, 10 its diameter (in mm), and L the distance between the beam and the rotor disk plane (in mm).

CAD files of the three rotors (ISAE 2, ISAE 3, and ISAE 4) are also provided

Example matlab codes to post-process results can also be found :

• For aerodynamic results , the thrust and power coefficients are given as a function of RPM. Typical temperature and fluid density values are 290K and 1.2kg/m3, respectively. In some cases, data exhibit relatively low values at a given RPM compared to those at other RPMs (e.g. ISAE_2_T10_L20_static at 7000 RPM), which might be due to vibrations of the test rig at this RPM.

• For acoustic results, the autopower (Pa2) is given as a function of the frequency (Hz). Autopowers are obtained from fluctuating pressure time signals (16s) by computing the fast Fourier transform (FFT) with a Hanning window applied on 100 segments, using a 50% overlap and a magnitude correction factor, which leads to a frequency resolution of 3.125 Hz.

Structure of acoustic data :

For each rotation speed, data from 13 microphones located 1.62m away from the rotor center and at different latitude angles (every 10 degrees) from the rotor plane are provided. Microphone 1 corresponds to +60 degrees (with respect to the rotor plane, where + indicates that it is located in the direction opposite of the flow, for our rotors blowing downward, please refer to Figure 1 from the publication). Microphone 2 corresponds to +50 degrees ... Microphone 7 corresponds to 0 degrees (the rotor plane) … Microphone 13 corresponds to -60 degrees. Moreover, the test rig is fixed on a turntable, which can rotate the entire rotor-beam setup in azimuth with a step angle of 10 degrees. With the couple directivity antenna/turntable, the almost complete spherical directivity can be investigated, only the poles (absolute value of latitude angle over 60 degrees) being missing. The definitions of latitude and azimuth angles are given in Figure 1 of the corresponding publication.

Matlab, R2020_b