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Results for “EVAPORATION MODEL”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Multiplicities of secondaries in interactions of 1.8 GeV/nucleon 56Fe nuclei with photoemulsion and the cascade evaporation model

A nuclear photographic emulsion method was used to study the charge-state, ionization, and angular characteristics of secondaries produced in inelastic interactions of 56Fe nuclei at 1.8 GeV/nucleon with H, CNO, and AgBr nuclei. The data obtained are compared with the results of calculations made in terms of the Dubna version of the cascade evaporation model (DCM). The DCM has been shown to satisfactorily describe most of the interaction characteristics for two nuclei in the studied reactions. At the same time, quantitative differences are observed in some cases.

Non-NASA Center↗
NASA NTRS1995

Multiplicities of secondaries in interactions of 1.8 GeV/nucleon Fe-56 nuclei with photoemulsion and the cascade evaporation model

A nuclear photographic emulsion method was used to study the charge-state, ionization, and angular characteristics of secondaries produced in inelastic interactions of Fe-56 nuclei at 1.8 GeV/nucleon with H, CNO, and AgBr nuclei. The data obtained are compared with the results of calculations made in terms of the Dubna version of the cascade evaporation model (DCM). The DCM has been shown to satisfactorily describe most of the interaction characteristics for two nuclei in the studied reactions. At the same time, quantitative differences are observed in some cases.

Dudkin, V. E↗
NASA NTRS2003

Marangoni Convection and Deviations from Maxwells' Evaporation Model

We investigate the convective dynamics of evaporating pools of volatile liquids using an ultra-sensitive thermal imaging camera. During evaporation, there are significant convective flows inside the liquid due to Marangoni forces. We find that Marangoni convection during evaporation can dramatically affect the evaporation rates of volatile liquids. A simple heat balance model connects the convective velocities and temperature gradients to the evaporation rates.

Segre, P. N.↗
DOE OSTI2023

CONDENSATION-EVAPORATION MODELING OF DRIFT FROM A MECHANICAL COOLING TOWER

Numerical studyfor investigatingthe phase change behavior of a drift from a mechanical draft cooling tower is presented. A k-ε turbulence model, discrete phase model, species transport equations, and a heat-mass exchange model are solved simultaneouslyto capture the heat and mass transfer effects of a drift condensing and evaporatingeffects. The simulation result is compared to an available real scale test data and its limitation is also discussed. A parametric study is carried out by varying the ambient dry bulb temperature, ambient relative humidity, wind speed, liquid droplet diameter, and the drift amount. It is found that by combining the evaporation and condensation models, a drift phase change phenomena is accurately depicted. A parametric study reveals that wind speed impact is affected by the ambient temperature and the number of liquid droplets and their size play a critical role in the phase change phen

Han, Kai↗
NASA NTRS2006

A New Finite-Conductivity Droplet Evaporation Model Including Liquid Turbulence Effect

A new approach to account for finite thermal conductivity and turbulence effects within atomizing droplets of an evaporating spray is presented in this paper. The model is an extension of the T-blob and T-TAB atomization/spray model of Trinh and Chen [9]. This finite conductivity model is based on the two-temperature film theory in which the turbulence characteristics of the droplet are used to estimate the effective thermal diffusivity for the liquid-side film thickness. Both one-way and two-way coupled calculations were performed to investigate the performance cf this model against the published experimental data.

Balasubramanyam, M. S.↗
NASA NTRS2003

Modeling evaporation of Jet A, JP-7 and RP-1 drops at 1 to 15 bars

A model describing the evaportion of an isolated drop of a multicomponent fuel containing hundreds of species has been developed. The model is based on Continuous Thermodynamics concepts wherein the composition of a fuel is statistically described using a Probability Distribution Function (PDF).

kerosene drops↗
DOE OSTI2022

Desalination Multi-Effect Evaporator Models in Support of Integrated Energy Systems

The purpose of this work is to contribute to the Integrated Energy Systems (IES) modeling efforts from the Department of Energy with Idaho National Laboratory. The DOE is working on a plug-and-play set of models in an open-source repository called HYBRID that can be used to improve IES modeling capabilities.

99 GENERAL AND MISCELLANEOUS↗
NASA NTRS1989

High-resolution X-ray spectra of solar flares. IX - Mass upflow in the long-duration flare of 1979 June 5

Blueshifted X-ray spectral line components in Fe and Ca spectra of a large long-duration flare observed on June 5, 1979. It is found that blueshifted emission exists for a time interval of at least 28 minutes indicating upflowing plasma at about 250 km/s. Emission measures for both the blueshifted and stationary plasma are derived and the results are interpreted in terms of chromospheric evaporation. The total amount of hot upflowing plasma during the flare rise time exceeds the amount of stationary plasma contained in the loop close to the time of the peak of the flare. This result contradicts the simplest version of the evaporation model. Evaporation can account for the observations only if some of the upflowing plasma cools on time scales much shorter than the rise time of the event, which was about 40 minutes.

Doschek, G. A.↗
NASA NTRS1979

Evaluation of a locally homogeneous model of spray evaporation

A model of spray evaporation which employs a second-order turbulence model in conjunction with the locally homogeneous flow approximation, which implies infinitely fast interphase transport rates is presented. Measurements to test the model were completed for single phase constant and variable density jets, as well as an evaporating spray in stagnant air. Profiles of mean velocity, composition, temperature and drop size distribution as well as velocity fluctuations and Reynolds stress, were measured within the spray. Predictions were in agreement with measurements in single phase flows and also with many characteristics of the spray, e.g. flow width, radial profiles of mean and turbulent quantities, and the axial rate of decay of mean velocity and mixture fraction.

Shearer, A. J.↗