Figure 2: Comparison of the instantaneous velocity field of unsteady RANS model
against the PANS model (top) and for the incompressible backstep flow (bottom)
Figure 3: Comparison of the internal shock structures for hypersonic engine in
Mach 5: (a) experimental observation, (b) SST k-omega simulation
designed based on a flying wing UAV concept built
with no tail and has no definite fuselage. This is
the most effective fixed wing design based on the
streamlined perspective and auxiliary weight. It has
high lift-to-drag ratio because of fewer edges, less
tip edge and less surface area design that reduces
parasitic drag. Hence, because it is lightweight and
has less drag, this design provides better-operating
costs for users. The aircraft is designed with a
1.3m wingspan and a fuselage length of 0.8m. It
has an aspect ratio of 4.91 with wing loading of
46g/sq.m. The maximum take-off weight (MTOW)
is 1.6kg.
The prototype is built from scratch using
expanded polystyrene (EPS) and expanded
polypropylene (EPP) foam as the base materials.
Usage of this material has several advantages
such as manufacturability, low cost and light
structure weight. For the fuselage section of
the prototype, EPP foam was used as it has low
density and high elasticity which means that
the material is lightweight and can absorb some
impact during flight without fracturing. For the
wing section, EPS foam material was used as it
is lightweight and easy to manufacture. A 4-axis
computer numerical control (CNC) machine was
used to fabricate straight shapes as well as
tapered shapes. This machine operates based on
the use of a temperature-controlled wire to melt
the foam material according to the computer-aided
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