In January of 1935, definite steps were taken in a two part program to modernize the ten-foot wind tunnel of the Guggenheim Aeronautical Laboratory at the California Institute of Technology. Part one of the program was the design and construction of a new wind tunnel rigging system based on concepts originally laid down by Dr. A. L. Klein, Associate Professor at the same institution. Part two of the program, to be carried on intensively immediately after completion of part one, will be the development of an entirely new force measuring system to replace the present modified steelyard type balances.
\r\n\r\nIn this paper the general problem of wind tunnel testing and equipment will be briefly outlined with the bulk of the discussion then given over to the problems concerning the evolution and design of a specific wind tunnel rigging system. As the system is not yet complete in its final form obviously there can be no description of the project as a finished piece of work. Also, it has been thought inadvisable to present only the system as it exists at present, therefore all the various features or principles that have been considered will be discussed and reason for their discard or adoption made clear. The result should then be a guide or at least an aid to the completion of part one of the modernizing program
\r\n\r\nIn a latter section of the paper some of the desired features of the contemplated force measuring system will be set down in the hope that they may be a skeletal set of requirements for the second part of the modernizing program.
\r\n", "doi": "10.7907/CVB4-7510", "publication_date": "1937", "thesis_type": "masters", "thesis_year": "1937" }, { "id": "thesis:1492", "collection": "thesis", "collection_id": "1492", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-04242008-111115", "primary_object_url": { "basename": "Childers_mc_1936.pdf", "content": "final", "filesize": 2602830, "license": "other", "mime_type": "application/pdf", "url": "/1492/1/Childers_mc_1936.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "Stresses in Metal Beams with Flat Sheet Webs of Medium Thickness", "author": [ { "family_name": "Childers", "given_name": "Milford Carlson", "clpid": "Childers-Milford-Carlson" } ], "thesis_advisor": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" } ], "thesis_committee": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" }, { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" }, { "family_name": "Millikan", "given_name": "Clark Blanchard", "clpid": "Millikan-C-B" }, { "family_name": "Sechler", "given_name": "Ernest Edwin", "clpid": "Sechler-E-E" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "This paper develops a method by which the stresses in the component parts of a solid web beam may be computed when the dimensions of the web thickness, beam height, and distance between stiffeners are such that the web does not go into the wave state immediately upon applying a small load. The stress in the web itself is calculated by a consideration of the buckling load of the web. The load in the stiffeners and flanges is computed by assuming an effective width of sheet as acting with them. This effective width is obtained by a consideration of the buckling properties of thin sheet in shear.
\r\n\r\nThe results are in the same form as the familiar Wagner beam equations except that certain terms must be modified and corrections made. The results herein obtained are not to be considered as superseding the Wagner Equations as derived in Ref. I, but supplement them to take care of cases out of the range of the Wagner assumptions.
\r\n", "doi": "10.7907/Y3QT-J764", "publication_date": "1936", "thesis_type": "masters", "thesis_year": "1936" }, { "id": "thesis:236", "collection": "thesis", "collection_id": "236", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-01192006-141156", "primary_object_url": { "basename": "Lipp_je_1935.pdf", "content": "final", "filesize": 8978709, "license": "other", "mime_type": "application/pdf", "url": "/236/1/Lipp_je_1935.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "Strength of Thin Walled Cylinders Subjected to Combined Compression and Torsion", "author": [ { "family_name": "Lipp", "given_name": "James Everett", "clpid": "Lipp-James-Everett" } ], "thesis_advisor": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" } ], "thesis_committee": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" }, { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" }, { "family_name": "Millikan", "given_name": "Clark Blanchard", "clpid": "Millikan-C-B" }, { "family_name": "Sechler", "given_name": "Ernest Edwin", "clpid": "Sechler-E-E" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "This thesis is an extension of the work which was started by Dr. Donnell and Lieutenant Bridget on the problem of thin metal cylinders under combined torsion and direct stress. An explanation of the shape of the compression vs. torsion curve is found by calculating the yield failure of an element of sheet considered as a column with both transverse and end loads. Several causes of variation in that curve shape have been brought to light, but must wait for very complete and accurate experiments or a complete theoretical treatment for verification.
\r\n\r\nExperiments have been extended to several new materials, and have given results which parallel the previous work on steel. In order to cover as wide a range of cylinders as possible, the data of reference no. 1 have been included with the present series of tests.
", "doi": "10.7907/6Z0W-XJ59", "publication_date": "1935", "thesis_type": "phd", "thesis_year": "1935" }, { "id": "thesis:1585", "collection": "thesis", "collection_id": "1585", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-05022008-122728", "primary_object_url": { "basename": "Mills_rh_1935.pdf", "content": "final", "filesize": 2084954, "license": "other", "mime_type": "application/pdf", "url": "/1585/1/Mills_rh_1935.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "The Boundary Layer for Some Axial Symmetric Flows", "author": [ { "family_name": "Mills", "given_name": "Roscoe Harlan", "clpid": "Mills-Roscoe-Harlan" } ], "thesis_advisor": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" } ], "thesis_committee": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" }, { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" }, { "family_name": "Millikan", "given_name": "Clark Blanchard", "clpid": "Millikan-C-B" }, { "family_name": "Tollmien", "given_name": "Walter", "clpid": "Tollmien-W" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "The following thesis consists of two sections. Part 1. deals with \"The Boundary Layer for Some Axial Symmetric Flows\", Part 2. with \"Preliminary Experiments on the Flow between Two Circular Disks\".", "doi": "10.7907/R7Q5-V769", "publication_date": "1935", "thesis_type": "phd", "thesis_year": "1935" }, { "id": "thesis:3166", "collection": "thesis", "collection_id": "3166", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-08182006-154158", "primary_object_url": { "basename": "Wattendorf_f_1933.pdf", "content": "final", "filesize": 31585026, "license": "other", "mime_type": "application/pdf", "url": "/3166/1/Wattendorf_f_1933.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "A Study of the Effect of Curvature on Fully Developed Turbulent Flow", "author": [ { "family_name": "Wattendorf", "given_name": "Frank Leslie", "clpid": "Wattendorf-Frank-Leslie" } ], "thesis_advisor": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" } ], "thesis_committee": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" }, { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" }, { "family_name": "Tollmien", "given_name": "Walter", "clpid": "Tollmien-W" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "In aeronautics we are especially interested in the flow of air adjacent to surfaces, such as airfoils. There are two main types of flow of real fluids, laminar and turbulent and it is turbulent flow which is of practical importance in aeronautics. We should like to be able to predict the skin friction and flow conditions for any surface of any shape. There has recently been much success with the problem of predicting flow along a flat plate parallel to the direction of flow, and the problem was attacked by investigation of fully developed turbulent flow in straight channels, and direct application of the semi-empirical laws obtained, to the flow along a flat plate. However, surfaces met with in practice are, in general, curved, so that it would be important to be able to predict the effect of curvature on turbulent flow. Most of the previous work in curved flow, however, has been with curved pipes and channels where the behavior of the flow was complicated by secondary vortices.
\r\n\r\nThe present work had the purposes of isolating as far as possible the effect of curvature on a fully developed turbulent flow, with two dimensional mean motion. The curved channels used were 5 cm. in breadth and 90 cm. in depth, and had straight entrance sections over 60 x breadth in length to produce a fully developed straight flow before subjecting it to the effect of curvature. Channel I had inner radius 45 cm. and outer radius 50 cm., while channel II had inner radius 20 cm. and outer 25 cm. In addition, measurements were made in an appratus consisting of two concentric cylinders, the inner one of radius 20 cm. and rotating, the outer of radius 25.4 cm. and fixed. The curvature was made of the same order as channel II for purpose of comparison.
\r\n\r\nMeasurements on the channels consisted of pressure drop along the channel walls at several speeds, velocity distribution at 30\u00b0 intervals around the curved portion, velocity distributions at several speeds, and for channel II, determination of the shearing stress at the walls of one of the curved sections.
\r\n\r\nMeasurements on the cylinders consisted of velocity distributions at two speeds and determination of shearing stress at the outer wall.
\r\n\r\nEvaluation of results included: calculation of resistance law, calculation of the shearing stress, distribution in radial direction across the curved portion, determination of the exponential law for the velocity distribution near the walls in the various cases, calculation of the \"mixing length\" 1, from turbulent exchange theory, and several dimensionless methods of plotting velocity distributions to show similarity between measurements in the channels and in the concentric cylinders.
\r\n\r\nAlso included are calculations of the laminar flow distribution in a curved channel, and a discussion of Rayleigh's stability criterion.
\r\n\r\nIt appears that the distribution of centrifugal force has a strong influence on the stability of the flow, and affects materially the velocity distribution. The fact that similarity can be obtained for several cases by proper dimensionless reduction based on the effective breadth of the mixing region looks hopeful, and it remains for future investigations to determine more facts about the effective breadth of the mixing region.
", "doi": "10.7907/RWZE-DP61", "publication_date": "1933", "thesis_type": "phd", "thesis_year": "1933" } ]