Author Archives: saemiller
Reflection on Twenty Years Since the Loss of Columbia
Graduate Student Garrison S. Osborne and Steven A. E. MillerUniversity of Florida Department of Mechanical and Aerospace Engineering Well before the loss of Columbia, the NASA Office of Technology Assessment wrote, “Shuttle reliability is uncertain, but has been estimated to range between 97 and 99 percent. If the Shuttle reliability is 98 percent, there would …
Continue reading “Reflection on Twenty Years Since the Loss of Columbia”
On Seminar with Professor Said Elghobashi
It is more rare to be inspired as time goes on. On occasion, it is a great priveledge to hear a seminar by a world expert in turbulence. In this case at University of Florida, we had Professor Said Elghobashi from University of California Irvine join us for department seminar. He can be credited with …
Continue reading “On Seminar with Professor Said Elghobashi”
Fontenelle on Science
We like to regard as useless what we do not know; it is a kind of revenge; and since mathematics and physics are rather generally unknown, they rather generally pass for useless. The source of their misfortune is plain; they are prickly, wild, and hard to reach …. Such is the destiny of sciences handled …
Aeroacoustic and Aerodynamic Interaction Effects Between eVTOL Rotors
My student presented his MS thesis on the aerodynamics and aeroacoustics of rotors. Abstract: Electric vertical take-off and landing (eVTOL) aircraft are characterized by their unconventional wing and electric rotor configurations, which involve both side-by-side and tandem rotor configurations. These configurations create unique aerodynamic and aeroacoustic flow-fields. We numerically investigate the interaction effects between rotor …
Continue reading “Aeroacoustic and Aerodynamic Interaction Effects Between eVTOL Rotors”
On Infinity by Euler
We may here deduce from it a few consequences that are extremely curious, and worthy of attention. The fraction $\frac{1}{\infty}$ represents the quotient resulting from the division of the dividend 1 by the divisor $\infty$. Now, we know, that if we divide the dividend 1 by the quotient $\frac{1}{\infty}$, which is equal to nothing, we …
Teller on Uncertainty
… we have a radioactive substance that emits, on the average, a particle, an alpha particle, once every second on the average. Now, here I have a counter, and I close that counter, so it won’t count, except that I open it for half a second. If, in that half a second, a particle arrives, …
On Large Language Models (AI) and Aerospace Education
Artificial intelligence (AI) is changing all aspects of our lives, much like the internet did when it became widely available to consumers in the mid-1990s. There are many discussions about how the AI revolution has affected different areas, including the workplace, art, culture, writing, and academics. Recently, the “ChatGPT: Optimizing Language Models for Dialogue” has …
Continue reading “On Large Language Models (AI) and Aerospace Education”
Codex Arundel
While reading Leonardo da Vinci’s Codex Arundel last evening, I noticed that the Codex had less scholars examining it relative to others. The fluid dynamics of da Vinci have been extensively studied, with entire dissertations dedicated to the subject. I came across a curious drawing that exhibited turbulent flow. The text is written backward in …
Additional Thoughts on Pressure
I am obsessed with pressure, particularly the internal pressure of fluids. Unlike viscosity, it is absent of frictional forces, and it is a key driving force in both human behavior and aerospace flows. Pressure is an essential component of a perfect fluid and appears on the right-hand side of the Navier-Stokes equations. Without pressure, fluid …