| viXra.org > Mathematical Physics > 2106 |
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| viXra.org > Mathematical Physics > 2106 |
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[7] viXra:2106.0170 [pdf] submitted on 2021-06-30 15:11:29
Authors: Michele Nardelli, Antonio Nardelli
Comments: 142 Pages.
In this research thesis, we analyze some equations concerning Weak Gravity Conjecture and Swampland. Furthermore, we obtain various mathematical connections with some Ramanujan formulas, Riemann zeta function and several sectors of String Theory
Category: Mathematical Physics
[6] viXra:2106.0157 [pdf] submitted on 2021-06-27 21:32:01
Authors: Shlomy Shitrit
Comments: 26 Pages.
The following study presents single and multipoint aerodynamic shape optimizations of two
benchmark problems defined by the Aerodynamic Design Discussion Group (ADODG). Mesh
warping and geometry parametrization is accomplished by fitting the multi-block structured grid
to a B-spline volumes and performing the mesh movements by using surface control points
embedded with free-form deformation (FFD) volumes. The aerodynamic model solves the RANS
equations with Spallart-Almaras turbulence model. A gradient based optimization algorithm is
used with an adjoint method in order to compute the objectives and constraints derivatives with
respect to the design variables. The objective in this work is to minimize the drag of airfoil and
wings for transonic regimes taking into account volume and thickness constraint, including
aerodynamic coefficients constraint.
The first problem solved is RAE2822 airfoil in viscous transonic flow, with a lift constraint. The
shock in the upper surface is eliminated and the drag coefficient is reduced by 50%. Also in this
problem we started the optimization solution from a circle in order to check the robustness of both
the flow solver and the mesh warping algorithm, while reaching a "close" solution as obtained by
starting from rae2822 airfoil. The second problem is single and multi-point lift and pitch moment
constrained drag minimization of the Common Research Model (CRM) wing in transonic, viscous
flow. The CRM design is very challenging due to the tight coupling between aerodynamic
performance, trim and stability. Other design challenges include the number of design variables
and its effect on the optimized configuration. The single-point optimization reduced the drag
coefficient by 7.7% using 192 design variables. The single-point designs are relatively robust to the
flight conditions. Further robustness is achieved through a multi-point optimization with nearly
5% drag reduction.
Category: Mathematical Physics
[5] viXra:2106.0150 [pdf] submitted on 2021-06-26 10:54:00
Authors: Guillermo Ayala-Martinez
Comments: 3 Pages.
By changing the variable each equation, from a velocity component, becomes a linear equation in which only that component appears. The convective acceleration terms are transformed into an only term. The new variable will be an independent variable and can be any suitable function.
Category: Mathematical Physics
[4] viXra:2106.0137 [pdf] submitted on 2021-06-23 06:41:44
Authors: Michele Nardelli, Antonio Nardelli
Comments: 58 Pages.
In this revisited research thesis, we analyze some equations concerning the Higher Spins and Strings - Supersymmetry Breaking and obtain various mathematical connections with various parameters of Particle Physics and several sectors of Number Theory.
Category: Mathematical Physics
[3] viXra:2106.0114 [pdf] replaced on 2021-07-01 12:58:31
Authors: J.A.J. van Leunen
Comments: 10 Pages. This is part of the Hilbert Book Model Project
Space can be covered with point-like objects. Space covered by a countable set of point-like objects behaves differently from space that is covered by an uncountable set of point-like objects. The document treats the consequences of the change in behavior.
Category: Mathematical Physics
[2] viXra:2106.0086 [pdf] submitted on 2021-06-14 08:16:52
Authors: Michele Nardelli, Antonio Nardelli
Comments: 129 Pages.
In this research thesis, we have analyzed some equations concerning “Power-law Inflation” (Lucchin-Matarrese attractor solution). We describe the possible mathematical connections with various expressions of Number Theory
Category: Mathematical Physics
[1] viXra:2106.0019 [pdf] submitted on 2021-06-03 23:01:17
Authors: Miftachul Hadi
Comments: Written in English, 1 page, no figure.
We reformulate Gauss-Bonnet-Chern theorem in relation with magnetic symmetry of geometrical optics. If Euler-Poincare characteristic is a topological invariant, should unrestricted electric potential of $U(1)$ gauge potential be a topological invariant?
Category: Mathematical Physics
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