Keyword: Heat transfer

Briefs: Medical

Sports-related injuries are a common cause of damaged ligaments and tendons in shoulders, knees, wrists, elbows and ankles, and can usually be repaired through arthroscopic surgery. Through an...

Briefs: Materials
Analysis of Multilayer Thermal Insulation for Reentry

A paper presents a study of multilayer thermal insulations for protecting spacecraft against aerodynamic heating during reentry into a planetary atmosphere. A multilayer insulation considered in the study comprised (1) thin ceramic/composite foils coated with gold for high reflectance...

Briefs: Information Technology
Initialized Fractional Calculus

The fractional calculus (which admits of integrals and derivatives of non-integer order) dates back almost to the origin of the better-known ordinary (integer-order) calculus, but thus far has been treated more as a mathematical curiosity than as a scientific and engineering tool. Increasingly many physical...

Briefs: Physical Sciences

Electrohydrodynamic (EHD) conduction pumps have been investigated in theoretical and experimental studies. In general, EHD pumps contain no moving parts. They generate pressure gradients and/or flows in...

Briefs: Software
Software Provides Thermal Optimization of a Computer CPU

Heat is the primary enemy of any electronic component. In order for an electronic device to have a long, problem-free life, cooling must be an important design consideration. The problem of cooling CPUs, in particular, has grown as processors have become more powerful. Water cooling...

Briefs: Software
Software for Implementing Fuzzy Logic on Microcontrollers

Fuzzy Inference System Translator (FIST) is a computer program that facilitates the implementation of fuzzy-logic software on commercial or other viable microcontrollers. In the original application for which FIST was developed, there was a need to implement plantgrowth- chamber (PGC)...

Briefs: Physical Sciences
Cold Flow Calorimeter

The cold flow calorimeter is an apparatus for measuring a possibly rapidly varying heat-transfer coefficient on a surface. The cold flow calorimeter includes (1) a small strain gauge bonded to a small, thin steel shim that is placed on the surface of interest and (2) a circuit that controls the electric power supplied to...

Briefs: Physical Sciences
Software for Simulating Two-Phase Systems

Møtran (signifying "multi-phase transient") is a package of software for simulating flows in two-phase (gas/liquid) fluid systems like networks of such components as pipes, T junctions, pumps, evaporators, and condensers. The software is based on a two-fluid formulation that can accommodate unequal...

Briefs: Mechanical & Fluid Systems
Improved Lightweight Freeze-Tolerant Tubes

Improved designs have been conceived for lightweight tubes that can withstand the large (as much as 8 or 9 volume percent) freeze/thaw expansions and contractions of typical heat-transfer fluids like water and ammonia. Intended originally for radiators for rejecting waste heat from spacecraft, these...

Briefs: Materials
Heat-Exchanger Rocket Engine

The proposed rocket engine includes a combustion chamber actively cooled by liquid oxygen: Heat from the combustion chamber vaporizes the flowing liquid oxygen, and the absorption of latent heat of vaporization contributes to cooling of the combustion-chamber wall. The resulting high-vapor-quality (mostly vapor)...

Briefs: Photonics/Optics
Software for Multidisciplinary Concurrent Optical Design

The Integrated Optical Design Analyzer (IODA) is a computer program that facilitates multidisciplinary concurrent engineering of highly precise optical instruments. (IODA should not be confused with a multidisciplinary optical-system-analysis program, called "IMOS," that has been reported...

Briefs: Motion Control

Engineers at Johnson Space Center have invented a relatively inexpensive, lightweight device that provides vibrational and thermal isolation for low-power electronic equipment. The...

Briefs: Physical Sciences

"Health check" would be built into pressure transducers, according to a proposal, to enable occasional, rapid, in situ testing of the transducers between normal pressure-measurement...

Briefs: Software
Program for Updating Parameters of Thermal Models

Parameter Identification in Thermal Networks (PITN) is a computer program developed to satisfy a need to update parameters in mathematical models of thermal systems in order to make the temperatures computed by the models equal to the temperatures measured in tests of the corresponding real...

Briefs: Physical Sciences
Model of Pyrolysis of Biomass in a Fluidized-Bed Reactor

A mathematical model has been formulated to describe the pyrolysis of biomass in a bubbling fluidized-bed reactor. The reactor is a vertical cylinder that contains a mixture of biomass particles and sand. Superheated steam enters the reactor through holes in the bottom and flows out freely...

Briefs: Software

Paper, tea, tobacco, and other food and industrial goods use drying tunnels to remove moisture from wet product sheets during manufacture. The tunnels operate using a fan to supply drying air to the...

Briefs: Motion Control

Experiments have shown that electrohydrodynamic pumping can be utilized to increase the heat-transport capacity of a heat pipe. More specifically, electrohydrodynamic pumping can...

Briefs: Mechanical & Fluid Systems

A Rankine-cycle engine that contains a binary working fluid (ammonia + water) and a recuperative heat exchanger has been built and tested. This engine is a prototype of...

Briefs: Physical Sciences

A device has been developed for measuring heat-transfer rates at many points underneath individual bubbles during boiling, in order to determine the heat-transfer coefficient as a function of...

Briefs: Physical Sciences
Controlling Crystal-Growth Habit in Directional Freezing

A method of controlling the crystal-growth habit in directional freezing has been devised. A substance can be purified by directional-freeze crystallization, wherein (1) the liquid phase of the substance is partially frozen, causing impurities to become preferentially concentrated in the...

Briefs: Motion Control

The heat-driven pulse pump has been invented in an effort to satisfy a need for pumps that can circulate heat-transfer fluids at low flow rates with high reliability over long operational lifetimes. The heat-driven...

Briefs: Physical Sciences
Computer Program for Analysis of Convective Heat Transfer

Glenn-HT is a computational fluid dynamics (CFD) computer code for the analysis of three-dimensional flow and convective heat transfer in a gas turbine. Glenn-HT has been evolving during the past few years at Glenn Research Center, and at least 35 technical papers relative to this code...

Briefs: Physical Sciences

Improved evaporators for loop heat pipes have been developed by incorporating bidisperse structures (in place of older monodisperse structures) into evaporator wicks. As explained in...

Briefs: Physical Sciences
Software for Probabilistic Thermal and Structural Analysis

NESTEM is a computer code that is a combination of a heat-transfer-analysis subprogram and a NASA in-house probabilistic-analysis code called "NESSUS" (for Numerical Evaluation of StochasticStructures Under Stress). NESTEM can be used to analyze a complex combustor thermal environment...

Briefs: Physical Sciences
SINDA/FLUINT Augmented To Represent Condensable Species

The Systems Improved Numerical Differencing Analyzer/Fluid Integrator (SINDA/FLUINT) software system has been upgraded by addition of a capability for simulating fluid mixtures that include condensable vapors. SINDA/FLUINT is the NASA standard software system for computational simulation...

Briefs: Robotics, Automation & Control

An improved system for densifying (by cooling) the liquid hydrogen and liquid oxygen used as propellants for the space shuttle has been proposed. These propellant liquids are...

Briefs: Physical Sciences
Evaporation of Isolated and Collections of Fluid Drops Under Supercritical Conditions

A report presents a computational study of heat and mass transfer for isolated and interacting drops of one fluid (liquid O2) immersed in another fluid (H2) in finite, quiescent surroundings under supercritical conditions. The mathematical...

Briefs: Materials

A magnetostrictively actuated heat switch has been proposed for use in a variety of cryogenic equipment, including adiabatic-demagnetization refrigerators, calorimeters, and coolers for...

Briefs: Materials

Improved aerogel-based thermal insulation systems have been developed to provide cost-effective and easier-to-handle alternatives to various types of multilayer insulation (MLI) and...