Other Aerospace Engineering Commons^™

Projectile Fire-Control Algorithm In A Spatially Varying Wind Field, Lakmal Kaviratna, Mark Costello, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

The fire-control solution is an important element of any modern weapon system, providing precise aiming of the gun to enable highly accurate projectile impact. To be practical, the fire-control solution must be computed rapidly and reliably while simultaneously including all pertinent physical effects that can alter the trajectory and impact point. Current fire-control solutions account for the effect of atmospheric wind in a rudimentary manner, typically assuming a constant crosswind that is estimated in the field or measured at the firing site. With the advent of advanced wind-measurement systems (light detection and ranging, for example), it is now possible to …

On The Benefits Of In-Flight System Identification For Autonomous Airdrop Systems, Michael Ward, Mark Costello, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

A unique feature of airdrop systems is the inherent and large variability in flight dynamic characteristics. The same physical article dropped on two different occasions will exhibit significantly different dynamic response. The problem only becomes worse for different test articles. Control systems for autonomous airdrop systems explicitly or implicitly assume knowledge of the flight dynamic characteristics in some way, shape, or form. A question facing autonomous airdrop designers is whether to use precomputed dynamic characteristics inside the control law, or to compute the needed flight dynamic characteristics in-flight and subsequently employ them in the control law. This paper establishes conditions …

Performance Of A Fire-And-Forget Anti-Tank Missile With A Damaged Wing, John Harris, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

A mathematical model is developed for an anti-tank missile and its guidance algorithms. The aerodynamic model is separated into two parts, the airframe and external lifting surfaces in order to model damage to the airframe. Radar data is compared to that of the proposed model and it is shown that the model accurately replicates the true flight dynamics. Two types of field handling damage are modeled, a damaged mid-body wing with 50% of its planform area missing, and an un-deployed mid-body wing. Monte Carlo simulations are performed for each type of damage and the eight possible mid-body wing locations. The …

The Cool Flames Experiment: Recent Results At Reduced And Partial Gravity, Michael R. Foster

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Cool flames at Earth (1g), Martian (0.38g), Lunar (0.18g) and reduced-gravity (10–2g) have been studied experimentally in a closed, unstirred, static reactor to better understand the role of natural convection and diffusive transport on the induction period(s), flame shape, flame propagation speed, pressure history and temperature profile. Natural convection is known to play an important role in all terrestrial, unstirred, static reactor cool flame and auto-ignition experiments when the Rayleigh number exceeds 600 [2,3,6]. At 1g, typical values of the Ra are 10^4-10^6.

In this paper, experimental results from static, unstirred reactor studies conducted at four different gravitational acceleration levels …