Numerical Modeling and Analysis of a Multi-rotor UAS
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Fig. 1 UAS with MRF domain
The frame is printed using ABS material to accommodate all the parts of quadcopter.
Factor of safety for the design is considered as 2, therefore thrust-to-weight ratio
of 2 is chosen. Hence, the maximum thrust required to lift the vehicle is 40 N. The
Fuselage shown in Fig. 1 has a diagonal length of 330 mm and height of 50 mm with
a total weight of 0.338 kg.
Four motors with suitable propellers are selected to produce approx. 1 kg thrust
each. Based on frame dimensions and estimated thrust, propellers of 8 × 4.5 inches
are selected. For 1 kg thrust motor, brushless motor 935 kV emax 2213 is used.
Figure 2 shows the physical assembly of the quadcopter.
3 Numerical Approach or Modeling
Computational domain is modeled based on the wind tunnel used for the analysis.
Figure 3 shows the computational domain with the model and its moving rotational
frames.
3.1 Mesh Generation
In simulations, mesh quality always plays a prominent role in obtaining results.
Quality of the mesh depends mainly on the skewness and orthogonality of the
elements in it. Hence the skewness and orthogonality values for the mesh are
controlled using element sizing option. From the calculations, it is observed that
173
Fig. 1 UAS with MRF domain
The frame is printed using ABS material to accommodate all the parts of quadcopter.
Factor of safety for the design is considered as 2, therefore thrust-to-weight ratio
of 2 is chosen. Hence, the maximum thrust required to lift the vehicle is 40 N. The
Fuselage shown in Fig. 1 has a diagonal length of 330 mm and height of 50 mm with
a total weight of 0.338 kg.
Four motors with suitable propellers are selected to produce approx. 1 kg thrust
each. Based on frame dimensions and estimated thrust, propellers of 8 × 4.5 inches
are selected. For 1 kg thrust motor, brushless motor 935 kV emax 2213 is used.
Figure 2 shows the physical assembly of the quadcopter.
3 Numerical Approach or Modeling
Computational domain is modeled based on the wind tunnel used for the analysis.
Figure 3 shows the computational domain with the model and its moving rotational
frames.
3.1 Mesh Generation
In simulations, mesh quality always plays a prominent role in obtaining results.
Quality of the mesh depends mainly on the skewness and orthogonality of the
elements in it. Hence the skewness and orthogonality values for the mesh are
controlled using element sizing option. From the calculations, it is observed that