The Fundamental Theorem of Algebra states that the field of complex numbers is algebraically closed, implying that every polynomial equation of degree n has n roots within the complex numbers, with at least one being a solution where the polynomial evaluates to zero. Historically, the theorem’s origin traces back to the conjectures by Albert Girard …
Category Archives: Mathematics
Personal Equation
1796, Maskelyne, Astronomer Royal of Britain, dismissed his assistant for what he believed to be persistent inaccuracies in the timing of observations, specifically delays of approximately half a second. This decision unknowingly set the stage for the development of an important concept in measurement science: the personal equation. Maskelyne’s published their mixed observational results. After …
Origins of Graph Theory
Graph theory emerged in the 18th century, connecting geometry with fields like topology and set theory. Leonhard Euler formulated graph theory during his time in Königsberg, now Kalingrad. His seminal work began with the 1736 paper, “The Seven Bridges of Königsberg.” Residents of Königsberg enjoyed crossing the city’s seven bridges in one outing – considered …
Revisiting \(e\) History
\(e\), defined by the limit \(\lim_{n \to \infty} \left(1 + \frac{1}{n}\right)^n\) and approximating 2.71828, is characterized by its irrational and transcendental nature, indicating it cannot be depicted as a quotient of two integers nor as a solution to any non-trivial polynomial equation with rational coefficients. John Napier, a Scottish mathematician and theologian, significantly contributed to …
Binary’s Origin
Binary numbers were originally used for encryption and communication, a fact recognized as early as the 17th century by Francis Bacon. Bacon used the binary system for encoding the alphabet using strings of binary characters. This laid the framework for subsequent developments in coded communication, such as technologies like the telegraph (Samuel Morse), which relied …
Creation of Probability
On chance – Ancient civilizations, despite their engagement in games of chance and divinatory practices, did not formalize the underlying principles of probability. The creation of formal probability theory is linked with gambling and divination, stretching back to antiquity. However, the mathematical formulation of chance / probability remained elusive until the 17th century surrounding the …
Saffman \(k-\omega^2\)
Saffman’s \(k-\omega^2\) turbulence model, initiated by Saffman’s research, plays a role in the two-equation models dedicated to turbulence research since the time of Kolmogorov in the 1940’s. The basics of Saffman’s model is shown in the portrayal of a statistically steady or ‘slowly varying’ inhomogeneous turbulence field alongside the mean velocity distribution. This model states …
Baldwin Barth One-Equation Model Reviewed
During the present semester, I reexamined the Baldwin-Barth one-equation turbulence model. This model constitutes a reformulation of the $k$ and $\epsilon$ equations, culminating in a single partial differential equation for the turbulent eddy viscosity, denoted as $\nu_t$, multiplied by the turbulent Reynolds number, $Re_t$. The model’s closure for the Reynolds-averaged Navier-Stokes (RANS) equations was a …
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Reflections on Spalart-Allmarus Turbulence Model, 2024
The Spalart-Allmaras turbulence model, a one-equation turbulence model, was a response to the inadequacies observed in zero-equation models, particularly their lack of predictive accuracy in complex flow scenarios such as wakes, shear layers, and shock wave boundary layer interactions. The creation of the Spalart-Allmaras model was influenced by multiple prior works, including the Baldwin Barth …
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AIAA Journal – Fully Parabolized Hypersonic Sonic Boom Prediction with Real Gas and Viscous Effects
https://doi.org/10.2514/1.J063425 Abstract: We present a methodology to predict the aerodynamic near-field and sonic boom signature from slender bodies and waveriders using a fully parabolized approach. We solve the parabolized Navier–Stokes equations, which are integrated via spatial marching in the streamwise direction. We find that unique physics must be accounted for in the hypersonic regime relative …