Classical Physics

Parametric Analysis of Fin Geometry Effects on Stability and Performance of a Model Rocket

Authors: Ayush Samanta
Comments: 9 Pages. (Note by ai.viXra.org Admin: Please cite listed scientific references)

Fin geometry plays a critical role in determining the aerodynamic stability andperformance of rockets, yet excessive fin area may reduce efficiency through added drag. In this study I investigated the effect of fin geometry on rocket flight characteristics using ten simulated variants analyzed in OpenRocket under controlled launch conditions with four wind levels in a hypothetical situation where we are in Guadalajara, Spain. Metrics including apogee altitude, maximum velocity, acceleration, and time to apogee were compared across designs, revealing measurable tradeoffs between stability margin and ascent performance. The results indicate that moderate fin configurations can outperform both oversized and undersized designs by balancing stability with reduced aerodynamic losses.
Category: Classical Physics

The Missing Rotation Angle of Rodrigues’ Rotation Formula

Authors: Russell P. Patera
Comments: 9 Pages.

Rodrigues’ Rotation Formula is used to rotate a vector based on the Axis-Angle parameterization of attitude transformation. Given an axis and angle about which an initial vector is rotated, Rodrigues’ Formula yields the final orientation of the vector. However, Rodrigues’ Formula does not include the associated rotation about the vector axis, which depends on the specific trajectory used in slewing the axis from its initial to final orientation. A theorem in attitude kinematics that was not available when Rodrigues developed his formula, contains attitude components that should be included with Rodrigues’ Formula. These attitude components were previously applied to the related problem of the Foucault Pendulum, which rotates with the Earth about the Earth’s spin axis. The methods to compute the rotation angle about the vector axis are the same as those used to compute the rotation of the Foucault Pendulum’s mounting fixture, since the trajectories are similar. This work presents the derivation of the formula for the missing rotation angle of Rodrigues’s Formula. Several numerical examples are presented to illustrate the use of the formula.
Category: Classical Physics

Simulations of Water Wave Generation Caused by Running Hydrofoil by Means of Wave-Making Green’s Function Due to 2-D Vortex

Authors: Tsutomu Hori, Manami Hori
Comments: 23 Pages, 13 Figures, 68 Equations, 10 References.

This paper conducts wave-making simulations for hydrofoils running at high speeds. The analysis is performed by constructing the wave-making Green's function due to a two-dimensional vortex filament by means of Fourier transform method. We adopt the developed Green’s function as the kernel function, and approach the problem using the boundary element method. The Green’s function is numerically computed by switching between three expansion forms, namely, Taylor expansion, continued fraction expansion, and asymptotic expansion, depending on the case.

Simulation calculations are performed on the lift force and wave-making resistance acting on the hydrofoil, the generated wave profile, the flow velocity vectors and the pressure distribution around the hydrofoil with a NACA airfoil. As a result, we gained concrete findings for the dependencies of wave-making phenomena upon the wing shape, running speed, submerged depth, angle of attack and other factors.
Category: Classical Physics

Calculate Universe 4 — Minimalistic Approach

Authors: Branko Zivlak
Comments: 3 Pages. 2 Tables (Note by viXra Admin: An abstract in the article is required)

Formulas are presented that connect known parameters in various fields of physics, thanks to the original concept and the Theory of Ruđer Bošković.
Category: Classical Physics

A Classical Mechanics Solution to Zeno's Arrow Paradox

Authors: Vladislav Smolenskij
Comments: 3 Pages. Added References section as requested by viXra Admin

The flying arrow paradox states that motion is impossible, as the arrow is motionless at every instant of time. Although the paradox has a mathematical solution, a physical uncertainty remains: is time continuous, or does it consist of numerous infinitesimally small intervals? Within the framework of classical mechanics, it is shown that the assumption of instantaneous rest (zero velocity at any moment) inevitably violates the laws of conservation of momentum and kinetic energy. A flying arrow cannot stop or resume its motion without external input. Consequently, the arrow cannot be "at rest" within an infinitesimally small interval of time, and/or time does not contain any "zeros" and flows continuously.
Category: Classical Physics

Verification Experiment of the "Electromagnetic Wave" Theory Based on a Half-Wave Dipole Dual-Antenna Pair

Authors: Hongyuan Ye
Comments: 15 Pages. (Note by ai.viXra.org Admin: Author name is required in the article after article title; and please cite and list scientific references)

Maxwell's equations theoretically introduce the hypothesis of "displacement current", stating that in a vacuum, a changing electric field can induce a changing magnetic field. Based on this, Maxwell predicted the existence of "electromagnetic waves" in a vacuum. The latest research indicates that the theory of "electromagnetic waves" has never been experimentally verified. The experiment conducted by German physicist Hertz in 1887 did not prove the existence of "electromagnetic waves" but rather demonstrated that wireless communication could be achieved by independent "electric field waves". Further research reveals that the hypothesis of "displacement current" is theoretically inconsistent. The simplest and most convincing way to verify the correctness of Maxwell's "electromagnetic wave" theory is to independently measure the electric field intensity and magnetic field intensity of electromagnetic radiation in wireless communication, and then determine through experiments whether the electric field energy density is equal to the magnetic field energy density. This verification experiment is based on the 3-meter method of EMC electromagnetic compatibility standards. A half-wave dipole dual-antenna configuration with reverse attenuation is used to cancel out the magnetic fields generated by the conduction currents of the two antennas, and the electric field intensity and magnetic induction intensity in the far-field of electromagnetic radiation are independently measured. The verification experiment shows that the electric field energy density is 137.6 times that of the magnetic field energy density, and the experimental result is 137.6 times the theoretical value of the "electromagnetic wave" theory. In this verification experiment, the relative error of the electric field intensity measurement is +/- 5%, and that of the magnetic field intensity measurement is +/- 40%. The experimental results are real and valid. This experiment fully proves that, whether in the near-field or far-field, the electromagnetic fields originate from the conduction current of the antenna. In a vacuum, without the participation of charges, a changing electric field cannot generate a changing magnetic field, and a changing magnetic field cannot generate a changing electric field. "Electromagnetic waves" do not exist in the objective physical world.
Category: Classical Physics

Understanding Magnetic Hose

Authors: Abhijit Bhattacharyya
Comments: 9 Pages. Data is available upon requet.

Fast magnetic flux control is important for circuit quantum electrodynamics (cQED) to control qubit precisely. The $3D$ superconducting microwave resonators posses higher volumes turning them to insensitive to surface dielectric losses resulting in higher $Q$ values in comparison to $2D$ resonators which have higher dissipation due to surface losses. Thus $3D$ resonators increase the decoherence time. Although this makes a strong reason to opt for $3D$ superconducting resonators while it is difficult to tune the qubit using fast magnetic field accurately from outside the $3D$ resonator. In this paper, we try to understand transporting the magnetic filed inside a cylindrical superconducting cavity implementing a cylindrical magnetic hose using finite element analysis.
Category: Classical Physics