Estimates for the aerodynamic coefficients of ringsail and disk-gap-band parachutes operating on Mars / Juan R. Cruz and Miranda L. Snyder.

Format:

Book

Government document

Author/Creator:

Cruz, Juan R., 1946-

Snyder, Miranda L., author.

Contributor:

Langley Research Center, issuing body.

Series:

NASA technical memorandum ; 2017-219619.

NASA/TM ; 2017-219619

Language:

English

Subjects (All):

Parachutes--Aerodynamics.

Parachutes.

Parachutes--Testing.

Genre:

Online resources.

technical reports.

Technical reports

Technical reports.

Physical Description:

1 online resource (xii, 101 pages) : color illustrations

Place of Publication:

Hampton, Virginia : National Aeronautics and Space Administration, Langley Research Center, October 2017.

Summary:

Models are presented for the aerodynamic coefficients of Supersonic Ringsail and Disk-Gap-Band parachutes as functions of total porosity, [lowercase Greek]Lambda(subscript italic T), Mach number, [italic]M, and total angle of attack, [lowercase Greek]Lambda(subscript italic T) (when necessary). The source aerodynamic coefficients data used for creating these models were obtained from a wind tunnel test of subscale parachutes. In this wind tunnel test, subscale parachutes of both parachute types were fabricated from two different fabrics with very different permeabilities. By varying the fabric permeability, while maintaining the parachute geometry constant, it was possible to vary [lowercase Greek]Lambda(subscript italic T). The fabric permeability test data necessary for the calculation of [lowercase Greek]Lambda(subscript italic T) were obtained from samples of the same fabrics used to fabricate the subscale parachutes. Although the models for the aerodynamic coefficients are simple polynomial functions of [lowercase Greek]Lambda(subscript italic T) and [italic]M, they are capable of producing good reproductions of the source data. The ([lowercase Greek]Lambda(subscript italic T), [italic]M) domains over which these models are applicable are clearly defined. The models are applicable to flight operations on Mars.

Contents:

Introduction

Source tests and data ; Wind tunnel test

Fabric permeability, effective porosity, and total porosity

Source data

Drag and total force coefficients modeling ; Static coefficients modeling

Concluding remarks

References

Appendix A. Data for the calculation of [lowercase Greek]Lambda(subscript italic T)

Appendix B. Static coefficients

Appendix C. Evaluation of other independent variables and regressors ; Other independent variables

Drag and total force coefficients modeling

Static coefficients modeling

Appendix D. Models for the static coefficients.

Notes:

Includes bibliographical references (page 24).

October 2017.

Online resource, PDF version; title from title page (NASA, viewed December 15, 2017).

OCLC:

1015370648