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Sutton, K.

Publications and source records attributed to Sutton, K..

31 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Langley Research Center entry aerothermodynamic technology development in support of Pioneer Venus multiprobe mission studies

A program of entry aerothermodynamics has been conducted to support the Pioneer Venus multiprobe mission. Aspects of the study include radiative property data, radiative blockage effectiveness measurements, heating calculations, aerodynamic and convective heating studies, and radio communications blackout models. Some of the historical background for the investigation is reviewed, and recommendations are made concerning the use of the developed technology in probe design and the continuation of certain elements of the program.

Olstad, W. B.↗
NASA NTRS1975

An analysis of communications blackout for Pioneer Venus entry probes

Estimates of the maximum duration of communications blackout are presented for a proposed Pioneer Venus mission involving a multiprobe entry targeted to individual impact sites. Calculations of the inviscid flow about the probes have been made using both finite-rate chemistry and equilibrium chemistry computer codes. Equilibrium boundary-layer calculations including ablation are also presented both with and without the presence of alkali metal contaminants from the heat shield. Methods are described for estimating maximum electron density in the inviscid wake and the recirculation region at the base of the probes. The results presented provide a conservative basis for planning for storage and subsequent telemetry of data during the entry phase of the mission.

Grose, W. L.↗
NASA NTRS1975

Radiative heating about outer planet entry probes

A study has been conducted to define the radiative, heating-rate distributions about spherically capped, 60 deg half-angle conical entry probes to the outer planets Jupiter, Saturn, and Uranus. The radiative heating rates are calculated by a direct method for the solution of the inviscid flow equations with coupled, nongray radiative transport. Results are presented for a range of entry conditions using the atmospheric models denoted as nominal, warm, and cool for each planet which show that both the magnitude and distribution of radiative heating rate are strongly dependent on the atmospheric model and the free-stream conditions.

Sutton, K.↗
NASA NTRS1974

Heating analysis for the Pioneer Venus multiprobe mission

The fully coupled, radiating flow field around the entry probes is determined from a detailed calculation which includes equilibrium chemistry, nongray radiative transport, ablation product injection, and a laminar or turbulent boundary layer. Results show that the radiative flux toward the body is attenuated in the boundary layer at downstream regions of the body as well as at the stagnation point and that, even when radiation absorption by ablation products is accounted for, the radiative heating rates along the downstream regions of the body can, under certain conditions, exceed the stagnation point values. It is also shown that, for Venusian entry, the spectral distribution of radiative flux and the magnitude of radiation absorption by ablation products depend strongly on entry velocity, and that the state of the boundary layer can significantly influence the amount of ablation product absorption or emission that occurs in various spectral regions.

Sutton, K.↗
NASA NTRS1973

Characteristics of Coupled Nongray Radiating Gas Flows with Ablation Product Effects About Blunt Bodies During Planetary Entries

A computational method was developed for the fully-coupled solution of nongray, radiating gas flows with ablation product effects about blunt bodies during planetary entries. The treatment of radiation accounts for molecular band, continuum, and atomic line transitions with a detailed frequency dependence of the absorption coefficient. The ablation of the entry body was solved as part of the solution for a steady-state ablation process. The method was applied by results at typical conditions during entry to Venus. The radiative heating rates along the downstream region of the body can exceed the stagnation point value. The radiative heating to the body is attenuated in the boundary layer at the downstream region of the body and at the stagnation point of the body. A study of the radiation, inviscid flow about spherically capped, conical bodies during planetary entries shows that the nondimensional, radiative heating distributions are nonsimilar with entry conditions. Caution should be exercised in attempting to extrapolate results from known distributions to other entry conditions for which solutions have not yet been obtained.

Sutton, K.↗
NASA NTRS1971

A general stagnation-point convective heating equation for arbitrary gas mixtures

The stagnation-point convective heat transfer to an axisymmetric blunt body for arbitrary gases in chemical equilibrium was investigated. The gases considered were base gases of nitrogen, oxygen, hydrogen, helium, neon, argon, carbon dioxide, ammonia, and methane and 22 gas mixtures composed of the base gases. Enthalpies ranged from 2.3 to 116.2 MJ/kg, pressures ranged from 0.001 to 100 atmospheres, and the wall temperatures were 300 and 1111 K. A general equation for the stagnation-point convective heat transfer in base gases and gas mixtures was derived and is a function of the mass fraction, the molecular weight, and a transport parameter of the base gases. The relation compares well with present boundary-layer computer results and with other analytical and experimental results. In addition, the analysis verified that the convective heat transfer in gas mixtures can be determined from a summation relation involving the heat transfer coefficients of the base gases. The basic technique developed for the prediction of stagnation-point convective heating to an axisymmetric blunt body could be applied to other heat transfer problems.

Sutton, K.↗