A model describing supercritical-pressure, multi-species turbulent mixing has been developed to simulate situations prevailing in diesel, gas turbine, and HCCI (homogeneous charge compression ignition) engines. It is also a situation occurring in atmospheric planetary science,...

Elementary-reaction chemical kinetics of hydrocarbon oxidation consists of hundreds to thousands of species and thousands of reactions. As such, it is impossible to use it in models and codes involving turbulence because computations are unfeasible due to lack of memory and...

Radiation-cooled, bipropellant thrust chambers are being used for in-space propulsion. To increase the performance of radiation-cooled engines, improved chamber materials are needed that will allow higher operating conditions (pressure and temperature), better resistance to oxidation, and...

At the time of this reporting, there have been no effective methods of monitoring current in conductors in space without breaking the circuit or making contact with the conductor. In space, reliability rules all designs, and breaking a circuit to insert a sensor to monitor current would reduce...

Two new fluidic actuator designs were developed to control fluid flow in ways that will ultimately result in improved system performance and fuel efficiency in to improve the aerodynamic performance of a variety of vehicles. These flow control actuators, often referred to as fluidic oscillators or sweeping jet...

This innovation presents a spacecraft aerobraking approach that reduces heating and optimizes corridors, which reduces overall risk. This is accomplished by combining solar panel aspect ratio and edge features with simple spacecraft packaging...

Combustion of realistic fuels is described by thousands of reactions involving thousands of species. Coupling these detailed chemical mechanisms with turbulence simulations is completely impractical because there is no computer powerful enough to solve the resulting equations.

Liquid sprays are commonly used to inject fuels into combustion devices, making it important to study multicomponent (MC) two-phase flows in order to reveal their physics. “Multicomponent” is the terminology describing all fuels that are combinations...

An improvement has been made to the infiltration of 3D woven and 3D braided preforms that will lead to the manufacture of CMC (ceramic matrix composite) and C–C (carbon-carbon) composites based on 3D fiber architectures that have low residual porosity and smaller void sizes. Tailoring the...

A document discusses a puncture self-healing polymer for space exploration that is capable of puncture healing upon impact. Puncture healing occurs instantaneously, providing mechanical property retention in lightweight structures.

A document describes a design optimization method for determining optimal shapes for vehicles with mid-range lift-to-drag ratios that are entering or re-entering planetary atmospheres. The design space includes consideration of hypersonic aerothermodynamic properties (for minimizing heating)...

Two coatings are required to remove/repel lunar dust particles from the mechanism or surface that needs protection. One coating must be a conductor, and one must be a dielectric. Tungsten carbide (WC) and aluminum oxide (Al2O3) were found to be best...

NASA missions employing mobility systems and other moving mechanical assemblies for application on Mars, the Moon, and in deep space depend on the reliable operation of these assemblies and their tribological components. Wet lubricants...

The idea of turning the stickiness of a material on and off is not an intuitive concept, yet this is exactly how geckos run up walls at speeds greater than 1 m/s and cling to ceilings made of glass. Transitioning this capability to spacecraft would constitute...

Atmospheric turbulences are fractional order, and because of that, it is difficult to simulate these disturbances. Past models fall short in providing sufficiently accurate simulation of atmospheric turbulence, especially at high altitudes, for control designs of high-speed atmospheric vehicles. In...

Oxidation chemical reactions of many practical fuels encompass thousands of species. When simulating complex turbulent reactive flows, it is impossible to account for the time and spatial evolution of all these species given current and foreseeable-future computer memory and time. This innovation...

A vehicle entering the atmosphere of a planet will do so at hypersonic speeds and will need to decelerate and maneuver through that atmosphere while protecting its payload from excessive heating. As a consequence, the vehicle shape must be designed to provide optimal aerodynamic lift and drag...

A new concept of aircraft aerodynamic control surfaces has been developed in connection with another new concept of active wing shaping control for reducing aircraft drag that will result in less fuel burn. The first concept is referred to as a variable camber continuous...

A previously created direct numerical simulation (DNS) database of mixing of species under supercritical pressure has been examined and analyzed for the purpose of understanding the modeling requirements in the context of large eddy...

A quantity called “the conserved scalar” is very important in the modeling of turbulent reactive flows in large eddy simulations because, if it can be defined, it numerically simplifies the solution of the conservation equations by confining the reaction term to a...

High-powered motors typically have very low resistance and inductance (R and L) in their windings. This makes the pulse-width modulated (PWM) control of the current very difficult, especially when the bus voltage (V) is high. These R and L values are dictated by the motor size,...