Articles:

Air Permeability of Parachute Cloths

M.J. Goglia

H.W.S. LaVier

C.D. Brown

Textile Research Journal, Vol. 25, No. 4, 296-313 (1955)

1955

The air permeability of 8 standard nylon parachute cloths was determined, using samples 6.05 in. in effective diameter. Fifty-nine experimental nylon cloths manu factured by the Bally Ribbon Mills were subjected to the same test procedure, as were 2 experimental fabrics of Orlon and Dacron, and 4 different samples of wire screen.

Upon assuming that the pressure gradient in the flow through a parachute fabric is proportional to the arithmetic sum of an inertial (ß2) and the viscous contribution (µ), the existence of a parameter, ß/ (whose measure is length), can be inferred. This length can be employed to characterize the geometry of the cloth. Experimental work to date in the case of the 8 standard nylon cloths, the Orlon and Dacron fabrics, 14 of the Bally Ribbon cloths, and the 4 wire screen samples indicates a justification of the assumption.

Employing the characteristic length so determined permits writing a single relation common to all cloths between a "flow-through-drag coefficient," Cr, and a Reynolds num ber based on the characteristic length, viz., Cf = 2 + (2/NRe).

A procedure is suggested for estimating the parameters and ß from physical meas urements for plain-weave cloth; thus an indication of the permeability is predicted from construction details of the fabric.

Green, Leon, and Duwez, Pol, "Fluid Flow Through Porous Media," J. Appl. Mech. 18: 1, 39-45 (March 1951 ).
Hoerner, S.F. , "Pressure Losses Across Screens and Grids," AF Tech. Rept. 6289 (November 1950 ).
Longnecker, Kenneth W., Development of a Theoretical Formula for Calculating Air Flow through Woven Materials under Certain Restricted Conditions, M.S. Thesis, Lowell Textile Inst. ( June 1950).
Penner, Stuart E., A Study of Flow Through Fabric-Like Structures , M.S. Thesis, Inst. of Textile Technology, Charlottesville, Va. (June 1950). Condensed in TEXTILE RESEARCH JOURNAL 20, 775 (1950).
Taylor, G.I. , and Davies, R.M., "Aerodynamics of Porous Sheets," Publication Board No. 92975, British Information Library, New York, [Bibliography of Sci. & Ind. Repts 10, 5 (November 1948)].
Anonymous, "Fabric-Porosity Testing Apparatus," Engineering (London ) 148: 3856, 634 (December 8, 1939). (WPA Bibliography on Aeronautics, Suppl. 5.)
Draper, S., Investigation of a New Method of Determining Porosity of Fabrics, Thesis, Mass. Inst. of Technology [TEXTILE RESEARCH JOURNAL 18, 650-658 (1948), from Backer's Thesis, Mass. Inst. of Technology].[Abstract/Free Full Text]
Landsberg, M.I. , and Winston, Gerald, "Relationship Between Measurements of Air Permeability by Two Machines," Pub. Board 97014 (Q.M.C. TSR 35).
Shinkle, John H., and Morean, Arthur J., "The Apermeter, A New Air Permeability Determination Apparatus," Am. Dyestuff Reptr. 36, 245-247 (May 5, 1947) [Textile Tech. Digest 4: 11, 459 (November 1947)].
Teres, J., and Sharnoff, P., "Calibration of Silk Porosity Meters," Rayon Textile Monthly 20: 10, 589-590 (October 1939) [Eng. Index (1939)].
Anonymous, "Gas Permeability ," Tech. News Bull. 328, 51-58 (1944) [Textile Tech. Digest 1: 4, 3 (September 1944)].
Brown, W.D., "Air Flow Through Materials Liable to be Used for Man-Carrying Parachutes with Special Reference to Celanese," E(RAE)TN Aero 1041 Reel 3757 Frame 905, Reel 3780 Frame 603 [Air Documents Index].
Brown, W.D., "The Effect of Tension on the Porosity of A Parachute Fabric," A.R.C., R & M 2325 (7543), Brit. Ministry of Supply, T.N. (January 1944).
Clayton, F.B. , "Measurement of Air Permeability of Fabrics ," J. Text. Inst. 26, T171-186 (1935 ) [TEXTILE RESEARCH JOURNAL 18, 650-658 (1948), from Backer's Thesis, Mass. Inst. of Technology ].[Abstract/Free Full Text]
Doetsch, H., "A Comparison of the Air Permeability of the Material to the Resistance of the Parachute," Z.W.B./FBI/ 230 Reel 2717 Frame 724 (January 1935) [Air Documents Index].
Glaskin, A. , "A Statistical Note on the Variation of Porosity of Nylon Fabric to Specification D.T.D. 556A," A.R.C., R & M 2313, Brit. Ministry of Supply, A.R.C., T.N. (June 1945).
Glaskin, A., "A Note on the Variation of Porosity of Cotton Fabrics to Specification D.T.D. 562 and D.T.D. 624," E/R.A.E./T.N. Aero 1664 Reel 3760 Frame 1451 [Air Documents Index].
Johns, T.F., and Anterson, E.I., "The Porosity of Nylon Fabrics for Man-Carrying Parachutes," E/R.A.E./T.N. Aero. 1176 Reel 3564 Frame 608 (April 1943).
Marsh, M.C. , "Some Notes on the Permeability of Fabrics to Air," J. Text. Inst. 22, T56-63 (1931 ) [C. A. 25, 5035 (1931)].
Rainard, L.W. , "Air Permeability of Fabrics: I," TEXTILE RESEARCH JOURNAL 16, 473-480 (1946) [TEXTILE RESEARCH JOURNAL 18, 640-648 (1948), from Backer's Thesis, Mass. Inst. of Technology].
Rainard, L.W. , "Air Permeability of Fabrics: II," TEXTILE RESEARCH JOURNAL 17, 167-170 (1947) [C.A. 41, 3630h (1947)].
Robertson, A.F., "Air Porosity of Open-Weave Fabrics. I: Metallic Meshes," Tech. Rept 1, Proj. 5007, Inst. of Textile Technology, Charlottesville, Va. [also TEXTILE RESEARCH JOURNAL 20, 838 (1950)].[Abstract/Free Full Text]
Robertson, A.F., "Air Porosity of Open Weave Fabrics. II: Textile Fabrics," Tech. Rept. 2, Proj. 5007, Inst. of Textile Technology, Charlottesville, Va. [also TEXTILE RESEARCH JOURNAL 20, 844 (1950)].[Abstract/Free Full Text]
Robertson, A.F., "Air Porosity of Open Weave Fabrics," TEXTILE RESEARCH JOURNAL 20, 838-857 (1950) [Engineering Index 51, 1622 (1951)].
Schiefer, H.E. , Cleveland, R.S., Porter, J.E., and Miller, J., "Effect of Weave on Properties of Cloth," Natl. Bur. Standards J. Research 11, 441-451 (1932) [TEXTILE RESEARCH JOURNAL 18, 650-658 (1948), from Backer's Thesis, Mass. Inst. of Technology].[Abstract/Free Full Text]
Siemenske, M.A., and Hotte, G.H., "The Permeability of Fabrics: I," Rayon Textile Monthly 26, 68-70 (1945) [Tech. Data Digest (AAF) 33 (March 1945)].
Siemenske, M.A., and Hotte, G.H., "The Permeability of Fabrics: II," Rayon Textile Monthly, 26, 61-62 (March 1945) [Tech. Data Digest (AAF) 36 (June, July 1945)].
Westbrook, F.A., "Permeability of Fabrics to Air and Water Vapor," Textile Mfr. 73, 451-453 (October 1947) [Textile Tech. Digest 5 (1948)].
Williams, K.A., Jr., The Air Permeability of Woven Fabrics, M.S. Thesis, Rensselaer Polytechnic Inst. (1949).
Alkan, R., "Contributions à l'étude à lessai des parachutes," Aeronautique 16, 179, 37-43 (April 1934) [Eng. Index (1934)].
Anonymous, "Report of Research and Experiments on the High-Speed Parachute," Tech. Intelligence, Air Mat. Com. Translation No. F-TS-430-RE (July 18, 1946).
Brown, W.D. , and Harrison, K., "Design of Parachutes for Large Bombs," Aero. Res-Council, R & M No. 2324 (5899), A.R.C. Tech. Rept. (1949).
Jarnagin, L.B. , "Phase of Parachute Problem," U.S.A.F., Air Tech. Intell.; Tech. Data Digest 13, 2, 7-12 (1948) [Eng. Index (1948)].
Johns, T.F. , "Parachute Design," Royal Aircraft Estab., Farmborough, Tech. Note No. Arm. 365 ( December 1946).
Johns, T.F. , and Picken, J., "Cotton Supplies-Dropping Parachutes: Tests with Containers Loaded to 500 Pounds," E/Royal Air Estab./T.N. Aero. 1554 Reel 3423 Frame 857 (November 1944) [Air Documents Index].
Madelung, Georg , "Report on the Works of the Parachute Department (Forschungsanstalt Gref. Zopplin)," Air Mat. Com., Tech. Intell. Summary Rept. No. F-SU-1107-ND (May 20, 1946).
Stevens, G.W.H. , "Experimental Work on Parachutes Used in Air Defense Apparatus," E/Roy. Air. Estab., Rept. No. Exc. 114 Reel 3432 Frame 633 (January 1942) [Air Documents Index].
U. S. Army Air Forces (T-2 Translation), "Report of Research and Experiments on the High-Speed Parachute," T-2 Translation 430 (July 1946).
Weinig, F.S. , "The Theory of the Parachute," Jahrb. deutsch. Luftfahrtforsch. I, 620-21 (1940) [P.B. 24231].
Weinig, F.S. , "Parachutes with Canopies Composed of Self-Supporting Ribbons," Tech. Intell., Air Mat. Com., Tech. Rept. No. F-TR-2148-ND (October 1947) [G.S.-A.A.F.-Wright Field No. 22].
Duncan, W.J. , "The Cause of the Spontaneous Opening and Closing of Parachutes (The Phenomena of Squidding)," Aero. Res. Council Tech. Rept., R & M No. 2119 (7293) (December 1943) [Brit. Min. of Supply].
Duncan, W.J. , Stevens, G.W.H., and Richards , G.J., "Theory of the Flat Elastic Parachute," Aero. Res. Council Tech. Rept., R & M No. 2118 (5893) (March 1942) [Brit. Min. of Supply].
Johns, T.F. , and Anterson, E.I., "The Effects of Various Factors on Parachute Characteristics," Aero. Res. Council, R & M 2335 (1950) [Aero. Eng. Rev. 9, 65 (October 1950)].
Jones, R.A. , "On the Aerodynamic Characteristics of Parachutes—A Complete Account of Researches Incorporated in Various Papers," submitted to the Advisory Committee for Aeronautics, Aero. Res. Council, A.C.R., R & M 862 ( June 1923 ).
O'Hara, F., "Notes on the Opening Behavior and the Opening Forces of Parachutes ," Roy. Aero. Soc. J. 53, 467, 1053-1062 (November 1949 [Aero. Eng. Index].
Scher, S.H., and Gale, L.J., "Wind Tunnel Investigations of the Opening Characteristics, Drag and Stability of Several Hemispherical Parachutes (NACA)," NACA Tech. Note 1869 (April 1949).
Simmons, L.F.G. , Gould, R.W.F., and Cowdrey , C.F., "Wind Tunnel Experiments on the Squidding of Parachutes," [Aero. Res. Council R & M No. 2523 (7062) (November 1943)].
Anonymous, "Rot Proof Parachute Canopy Fabrics," Roy. Aircraft Estab., Farmborough, Rept. CN No. 742 [Tech. Data Digest (AAF) (August 1945)].
Anonymous, "Parachutes and the New Fabrics They Require," Textile World 93, 10, 65-68 (October 1943) [Eng. Index (1943)].
Appel, W.D. , and Warner, R.K., "Investigation of Cotton for Parachute Cloth," IVACA Tech. Note 393 (September 1931) [Eng. Index ( 1931)].
Backer, Stanley , "The Relationship between the Structural Geometry of Textile Fabrics and Their Physical Properties," P.B. 95956 (Q.M.C. T.S.R. No. 52) (August 1948) [Bibliography of Sci. & Ind. Repts. 11: 3, 249 (March 1949)].
Bartell, F.E. , Purcell, W.R., and Dodd, C.G., "Measurement of the Effective Pore Size and of the Water Repellency of Tightly Woven Textiles," Disc. Faraday Soc. 3, 257-264 (1948) [Text. Tech. Digest].[CrossRef]
Brown, W.D. , "A Note on the Development of Artificial Silk for Parachutes with Special Reference to Their Use on U. S. Army Stores," E/Roy. Air. Estab./T.N. Aero. 1457 Reel 3785 Frame 997 (June 1944).
Cleary, C.J. , "Textile Materials Used in Aircraft," Silk J. & Rayon World 17: 198, 21-23 (November 1940) [Eng. Index (1940)].
Cleary, C.J. , "Parachute Fabrics," Airway Age 10: 11, 1766-1768 (November 1929) [Eng. Index (1929)].
Hamburger, W.J., "Effect of Yarn Elongations on Parachute Fabric Strength," Rayon Textile Monthly 23: 3, 151-153; 5, 291-292; 6, 332-334 (1942). Also Silk J. & Rayon World 19: 222, 27-29 (1942) [ Eng. Index (1942)].
Heinrich, Helmut , "Tests on Stability of Parachutes and Development of Parachutes of Standard Permeable Fabrics," P.B. 37256 (1943).
Johns, T.F. , and Hallum, M.E., "Note on the Useful Life of Silk Parachutes Used by Paratroops," E/Roy Aircraft Estab./T.N. Aero 1405 Reel 3653 Frame 658 (1944) [Air Documents Index].
McNicholas, H.J., and Hedrick, A.F., "The Structure and Properties of Parachute Cloths," NACA Tech. Note No. 335 (March 1930) [Eng. Index ( 1930)].
Pierce, F.T. , "Geometrical Principles Applicable to the Design of Functional Fabrics," TEXTILE RESEARCH JOURNAL 17, 123-147 (1947) [TEXTILE RESEARCH JOURNAL Abs. 18, 650-658 (1948), from Backer's Thesis, Mass. Inst. of Technology].[Abstract/Free Full Text]
Anonymous, "Navy Testing American Silk Cloth for Parachutes," U. S. Air Services 12: 5, 27 (May 1927) [WPA Bibliography on Aeronautics, p. 24].
Anonymous, "Physical Characteristics of Parachute Cloth under Varying Atmospheric Conditions," U. S. Govt. Printing Office, Air Corps Info. Circ. 651 (1930) [WPA Bibliography on Aeronautics, p. 24].
Battles, H.G. , "Neoprene Coated Nylon Rip-Stop Parachute Fabric ," P.B. 95555 (September 1948) [Bibliography of Sci. & Ind. Repts. 11, 1 (January 1949)].
Black, J., "Trustworthiness in Fabrics Vital in Parachute Use," Textile World 78: 4, 28-30 (July 26, 1930) [Eng. Index (1930)].
Brown, C.D., A Study of the Laws of the Flow of Fluids Through Fabrics, Unpublished Thesis, Georgia Institute of Technology.
Fluid Meters Report, 4th Ed., Am. Soc. Mech. Engrs., New York (1947).
Goglia, M.J., "Air Permeability of Parachute Cloths," Wright Air Development Center Rept. 52-283 (November 1952).
Holgate, B.A. , "Parachutes and Parachute Materials Used in Germany," F.I.A.T. 465 (P.B. 3882) (1945) [F.I.A.T. Rept. Office of Tech. Service, Dept. of Commerce (January 1948)].
Johns, T.F. , "Parachutes with an Axial Cord as Well as Cords over the Canopy," A.R.C. R & M 2336 (1944).
Laroso, P., and Burton, A.C., "Parachutes," B.I.O.S. Evaluation Rept. 477 (March 1946) [Bibliography of Sci. & Ind. Repts].
Smith, Julian F., "Records of Fabrics, Cords and Designs Developed for Personnel, Cargo and Projectile Parachutes," F.I.A.T. 453 (P.B. 3874, 1-388) (1945) [F.I.A.T. Bibliography, Dept. of Commerce].
Stevens, G.W.H. , and Johns, T.F., "The Theory of Parachutes with Cords over the Canopy," Aero. Res. Council, Tech. Rept. R & M No. 2320 (6068) (July 1942).
U. S. Aeronautical Board, " Cloth: Parachute, Saponified Acetate," Army-Navy-CCC-C-491-1 [P.B. 21268].
U. S. Navy Bureau of Ordnance, "Viscose Rayon Parachute Fabric," Naval Ordnance Spec . 1309 (January 1944) [P.B. 36085].