Engineering topics

Bolz, C. W., Jr.

Publications and source records attributed to Bolz, C. W., Jr..

4 records

NASA NTRS1979

A marching method for calculating line and continuum radiation in high energy flow fields

A method is presented for calculating nongrey radiative fluxes and intensities in a highly ionized, low temperature plasma with extreme line broadening. The method was developed to study radiative heating phenomena in the mass-injected hypersonic shock-layer environments characteristic of outer planet atmospheric entry, although it is not limited to such studies. The radiative properties model assumed local thermodynamic equilibrium and used standard continuum and molecular band models. The atomic line model, however, used a frequency-marching method for the frequency integration, which not only accounted completely for line overlapping (reabsorption) effects, but compared favorably in economy with the best equivalent-width methods. An assessment of hydrogen line-far-wing treatments, with recommendations for engineering models, is also presented.

Bolz, C. W., Jr.↗

NASA NTRS1976

Aerothermal environment for Jovian entry probes

Results are presented that describe the aerothermal environment encountered by the forebody of probes during Jovian entry. Two probe configurations are considered: a 55 deg half-angle spherically blunted cone and a 50 deg half-angle hyperboloid. The main emphasis is focused on defining the heating environment during entry and on determining the effectiveness of coupled ablation injection in reducing the surface heating rate. This is accomplished by calculating both the convective and radiative heating at several points along the entry trajectory both with and without coupled ablation injection. Results are presented for both laminar and turbulent calculations.

Moss, J. N.↗

NASA NTRS1976

An algorithm for selecting a radiation transport subgrid for ablation and radiation coupled hypersonic viscous shock-layer problems

An algorithm is described for selecting a grid subset for calculating radiative transport. The subset spacing is determined by using the variation in aerothermal properties across the full grid of the shock layer. Results show that a radiation grid subset of 15 to 20 points can be used for viscous-shock layer calculations where approximately 50 grid points are required to define the aerothermal profiles. Results are presented for various planetary entry conditions with and without mass injection to demonstrate both the validity and utility of the algorithm.

Bolz, C. W., Jr.↗

NASA NTRS1975

Viscous-shock-layer solutions with radiation and ablation injection for Jovian entry

This paper presents results that describe the flow field and surface response conditions for a planetary probe entering the atmosphere of Jupiter. The results are obtained with a viscous-shock-layer analysis which includes mass injection, radiative transfer, diffusion, and viscous effects. Radiative transfer is calculated with an existing nongray radiation model that accounts for molecular band, atomic line, and continuum transitions. Particular emphasis is given to the effect of mass injection on the stagnation and downstream flow. Results for both specified and coupled mass injection are obtained for a carbon heat shield.

Moss, J. N.↗