Estimating Basic Preliminary Design Performances of Aerospace Vehicles

Aerodynamics and Performance Estimation Toolset is a collection of four software programs for rapidly estimating the preliminary design performance of aerospace vehicles represented by doing simplified calculations based on ballistic trajectories, the ideal rocket equation, and supersonic wedges through standard atmosphere. The program consists of a set of Microsoft Excel worksheet subprograms. The input and output data are presented in a user-friendly format, and calculations are performed rapidly enough that the user can iterate among different trajectories and/or shapes to perform "what-if " studies. Estimates that can be computed by these programs include:

Ballistic trajectories as a function of departure angles, initial velocities, initial positions, and target altitudes; assuming point masses and no atmosphere. The program plots the trajectory in two-dimensions and outputs the position, pitch, and velocity along the trajectory. The "Rocket Equation" program calculates and plots the trade space for a vehicle's propellant mass fraction over a range of specific impulse and mission velocity values, propellant mass fractions as functions of specific impulses and velocities. "Standard Atmosphere" will estimate the temperature, speed of sound, pressure, and air density as a function of altitude in a standard atmosphere, properties of a standard atmosphere as functions of altitude. "Supersonic Wedges" will calculate the free-stream, normal-shock, oblique-shock, and isentropic flow properties for a wedge-shaped body flying super-sonically through a standard atmosphere. It will also calculate the maximum angle for which a shock remains attached, and the minimum Mach number for which a shock becomes at-angle, altitude, and Mach number.
Posted in: Briefs, Mechanical Components, Mechanics, Design processes, Computer software and hardware

Lightweight Deployable Mirrors With Tensegrity Supports

Extremely lightweight, deployable structures could be made by assembling tensegrity modules.

The upper part of Figure 1 shows a small-scale prototype of a developmental class of lightweight, deployable structures that would support panels in precise alignments. In this case, the panel is hexagonal and supports disks that represent segments of a primary mirror of a large telescope. The lower part of Figure 1 shows a complete conceptual structure containing multiple hexagonal panels that hold mirror segments.

Posted in: Briefs, Mechanical Components, Mechanics, Mirrors

SiC-Based Miniature High-Temperature Cantilever Anemometer

SiC-Based Miniature High-Temperature Cantilever Anemometer This compact, minimally intrusive sensor functions at temperature as high as 600 °C

The figure depicts a miniature cantilever- type anemometer that has been developed as a prototype of compact, relatively nonintrusive anemometers that can function at temperatures up to 600 °C and that can be expected to be commercially mass-producible at low cost. The design of this anemometer, and especially the packaging aspect of the design, is intended to enable measurement of turbulence in the high-temperature, high-vibration environment of a turbine engine or in any similar environment.

Posted in: Briefs, Mechanical Components, Mechanics, Test equipment and instrumentation

Inlet Housing for a Partial-Admission Turbine

Inlet Housing for a Partial-Admission Turbine The housing is shaped to smooth the inlet flow.

An inlet housing for a partial-admission turbine has been designed to cause the inlet airflow to make a smooth transition from an open circular inlet to an inlet slot. The smooth flow is required for purposes of measuring inlet flow characteristics and maximizing the efficiency of the turbine.

Posted in: Briefs, Mechanical Components, Mechanics, Gas turbines

Rotating Reverse-Osmosis for Water Purification

Rotating Reverse-Osmosis for Water Purification This device would resist fouling.

A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse-osmosis membranes are vulnerable to concentration polarization — a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water.

Posted in: Briefs, Mechanical Components, Mechanics, Water treatment

Instrument for Measuring Extreme Winds

This rugged instrument has no moving parts.

An instrument is undergoing development for use in measuring both the horizontal direction and the horizontal speed of wind in the speed range from 60 to 300 mph (about 27 to 134 m/s) at a rate of at least 50 samples per second. The speed range of this instrument greatly exceeds that of conventional anemometers, encompassing speeds observed in hurricanes and tornadoes. Unlike conventional anemometers, this instrument has a small exposure profile and contains no rotating mechanisms and, hence, is more rugged.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Wind power, Test equipment and instrumentation

Emergency Landing Using Thrust Control and Shift of Weight

Landing with control surfaces and engines on one side inoperative may be possible.

Normally, the damage that results in a total loss of the primary flight control of a transport airplane, including all the engines on one side, would be catastrophic. Dryden Flight Research Center has conceived of a method of responding to a total loss of hydraulic pressure and failure of engines on one side: An emergency controller would utilize the engines that are still working on the other side, along with transfers of fuel among tanks to effect lateral shift of the center of gravity (CG), in order to steer the airplane to an emergency landing.

Posted in: Briefs, Mechanical Components, Mechanics, Disaster and emergency management, Emergency management, Entry, descent, and landing

Magnetic Couplings for Gas-Driven Catapults

Projectiles would move along the outsides (instead of the insides) of launching tubes.

A proposed magnetic-coupling scheme would afford additional degrees of freedom to optimize the designs of gas-driven catapults or launchers. The scheme could be applied to gas guns in diverse applications, including launching spacecraft or aircraft, propelling various objects at high speeds along the ground, and accelerating objects to high speeds for research on hypervelocity impacts.

Posted in: Briefs, Mechanical Components, Mechanics, Launch vehicles

Systems for Dynamic Control of Growth of Protein Crystals

Key parameters that affect crystallization can be monitored and controlled.

Computer-controlled laboratory apparatuses for real-time monitoring and control of the growth of protein crystals are undergoing development. By use of an apparatus of this type, one can monitor and control several parameters that affect the growth of protein crystals; these parameters include temperature, pH, ionic strength, concentration of solute, rate of change of concentration of solute, and possibly others. One can utilize the monitoring capabilities to make decisions on the basis of the measured parameters. One can utilize the control capabilities to effect precise control of growth; one can also start, stop, or reverse growth at will.

Posted in: Briefs, Mechanical Components, Mechanics, Test equipment and instrumentation

Program for Computing Dynamics of Multiple Bodies

Relative to other programs used previously for the same purpose, computation times are reduced.

Symbolic Generator-Based Efficient Multibody Dynamics Algorithm (SOMBAT) is a program that enables speedy and accurate computations that solve equations of motion of multiple bodies. Originally intended for space-based applications (i.e., solving equations for the dynamics of a cluster of flexible bodies in orbit in real time), SOMBAT can also be applied in designing drugs, enhancing and otherwise processing images, the automotive industry, and robotics. It can also be used by the Department of Defense. Its greatest strength is its ability to reduce computation time without sacrificing accuracy. Unlike programs modeled on n3 algorithms, SOMBAT accrues time savings overruns while satisfying short-turnaround requirements. Moreover, and vitally for the U.S. Space Program, the open and expandable format of SOMBAT will enable the tailoring of this program to upgrade add-on systems for new International Space Station (ISS) modules.

Posted in: Briefs, Mechanical Components, Mechanics, Mathematical models, Computer software and hardware, Reliability

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