In the design of the Vertical Velocity Meter a survey was first conducted of the existing methods used to measure the vertical velocity of an airplane when landing. A study was then made of these methods and of other unsuccessful attempts to design a Vertical Velocity Meter to determine just why they were not satisfactory and in what way they might be improved.
\r\n\r\nIt was decided to develop a design along an entirely different principle than any used before but yet one having basic simplicity. The one selected was based on the formula of velocity being equal to a distance divided by the time it took to travel that distance. To accomplish this a device was designed which consisted of two rods of different length which would strike the ground when the plane was landing, thus if the difference in length and the time between the striking of the two rods is known, the velocity at that moment would be determined.
\r\n\r\nSince it was impracticable to test this device on an airplane, a testing machine was constructed which would test both the strength of the rods and various timing methods. This machine consisted of a wedge mounted on the end of a whirling arm which would strike the rods and simulate the impact received during the landing of an airplane. Two timing methods were tried; a Miller Oscillograph with built in recorder, and a Cathode-Ray Oscilloscope with a camera to record the trace.
", "doi": "10.7907/R4C9-D634", "publication_date": "1947", "thesis_type": "engd", "thesis_year": "1947" }, { "id": "thesis:4430", "collection": "thesis", "collection_id": "4430", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-11062008-151722", "primary_object_url": { "basename": "Lapin_e_1941.pdf", "content": "final", "filesize": 4636755, "license": "other", "mime_type": "application/pdf", "url": "/4430/1/Lapin_e_1941.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "The Effect of Gunfire on the Longitudinal Motion of an Airplane", "author": [ { "family_name": "Lapin", "given_name": "Ellis", "clpid": "Lapin-Ellis" } ], "thesis_advisor": [ { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" } ], "thesis_committee": [ { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" }, { "family_name": "Millikan", "given_name": "Clark Blanchard", "clpid": "Millikan-C-B" }, { "family_name": "Stewart", "given_name": "Homer Joseph", "clpid": "Stewart-H-J" }, { "family_name": "Biot", "given_name": "Maurice A.", "clpid": "Biot-M-A" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "The effect produced by the reaction forces and moments resulting from the fire of light and heavy calibre rapid fire guns on the path of motion of a modern military aircraft is discussed. This discussion is made on the basis of the \"exact\" equations of motion as developed by Bryan, Routh, and others, using the forms given in Dr. C. B. Millikan's notes on the dynamic stability of the airplane. The formal solution is made by the use of Heaviside operational calculus.\r\n\r\nFor general use there is developed a nomogram based on a series solution to the differential equations of motion. The application of this nomogram is illustrated and it is shown to give an easy and rapid approximation to the disturbance, and a sufficiently accurate one within the time ranges required. Since the exact solution requires several hours and the use of an experienced computer on a computing machine while the nomogram permits slide rule computations and results in a solution within a few minutes, its usefulness is readily apparent. The extension of the methods used in this paper to disturbed lateral motions is briefly discussed.\r\n", "doi": "10.7907/GQG7-6C62", "publication_date": "1941", "thesis_type": "engd", "thesis_year": "1941" }, { "id": "thesis:9190", "collection": "thesis", "collection_id": "9190", "cite_using_url": "https://resolver.caltech.edu/CaltechTHESIS:10012015-161848918", "type": "thesis", "title": "Strength of Thin-Walled Elliptical Cylinders Supported at the Minor Axis", "author": [ { "family_name": "Howland", "given_name": "Walter Lavern", "clpid": "Howland-Walter-Lavern" } ], "thesis_advisor": [ { "family_name": "von K\u00e1rm\u00e1n", "given_name": "Theodore", "clpid": "von-K\u00e1rm\u00e1n-Th" }, { "family_name": "Sechler", "given_name": "Ernest Edwin", "clpid": "Sechler-E-E" }, { "family_name": "Millikan", "given_name": "Clark Blanchard", "clpid": "Millikan-C-B" }, { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" } ], "thesis_committee": [ { "family_name": "Unknown", "given_name": "Unknown" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "In this investigation it was found that the\r\ninstability failure of curved sheet is nearly\r\nindependent of the type of loading and is primarily\r\na function of the maximum stress, radius-thickness\r\nration and modulus of elasticity. A method of\r\ncorrelating the critical stress of thin sheet\r\nunder several different types of loading is given.\r\nAn explanation for the experimental critical stress\r\nof thin walled cylinders under bending being\r\ngreater than that for pure compression is given.\r\nThe strength of unstiffened thin walled circular\r\nnose sections under pure bending was found to be \r\ncontrolled by local instability of the section,\r\nrather than a large scale instability. The equation\r\nof local instability of curved sheet gives values\r\nwhich are in fair agreement with those found experimentally.
\r\n\r\nThe strength of elliptical cylinders supported\r\nat the minor axis under bending plus shear loads is\r\ngoverned primarily by the bending strength, and is\r\nlittle effected by the sheer force unless the amount\r\nof shear is quite large with respect to the moment.\r\nThe effect of increasing the amount of elliptically\r\ngreatly reduces the bending and shear strength of nose\r\nsections. Under torsional loads the stress at\r\nbuckling falls off as the ration of the major to minor \r\naxis increases but the failure stress decreases\r\nat a slower rate than the buckling stress. The\r\nlength effect of semi-circular sections under torsion\r\nis similar to that of a circular tube, and can be\r\nobtained by Donnell's theoretical equation.
\r\n", "doi": "10.7907/KQK7-V396", "publication_date": "1939", "thesis_type": "phd", "thesis_year": "1939" }, { "id": "thesis:4065", "collection": "thesis", "collection_id": "4065", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-10132005-103946", "primary_object_url": { "basename": "Allardt_fh_1937.pdf", "content": "final", "filesize": 3162880, "license": "other", "mime_type": "application/pdf", "url": "/4065/1/Allardt_fh_1937.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "The Brinelling of Small Ball Bearings", "author": [ { "family_name": "Allardt", "given_name": "Frederick Hamilton", "clpid": "Allardt-Frederick-Hamilton" } ], "thesis_advisor": [ { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" }, { "family_name": "Sechler", "given_name": "Ernest Edwin", "clpid": "Sechler-E-E" } ], "thesis_committee": [ { "family_name": "Unknown", "given_name": "Unknown" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "The brinelling of ball bearings is a subject which has had comparatively little study. Since ball bearings have found most of their applications in such things as rotating shafts, there has been little reason to study their action under static loading conditions. This research was suggested by the Fafnir Ball Bearing Company because of the increasing use of ball bearings for static loads in aircraft. In the aircraft business, the designers, because of strict weight requirements, have used ball bearings up to their rated loads. Not infrequently these bearings brinelled. (A brinelled bearing is one in which a dent has been formed in one of the races by a ball). It is therefore evident that more should be known about the brinelling of bearings.", "doi": "10.7907/K872-W635", "publication_date": "1937", "thesis_type": "masters", "thesis_year": "1937" }, { "id": "thesis:1093", "collection": "thesis", "collection_id": "1093", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-03242005-100937", "type": "thesis", "title": "A Two-Parameter Wind Tunnel Rigging System", "author": [ { "family_name": "Young", "given_name": "Bradley Hobart", "clpid": "Young-Bradley-Hobart" } ], "thesis_advisor": [ { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" } ], "thesis_committee": [ { "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" }, { "family_name": "Bowen", "given_name": "William H.", "clpid": "Bowen-W-H" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "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:2907", "collection": "thesis", "collection_id": "2907", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-07172007-081411", "primary_object_url": { "basename": "Magden_jl_1934.pdf", "content": "final", "filesize": 5525494, "license": "other", "mime_type": "application/pdf", "url": "/2907/1/Magden_jl_1934.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "A Preliminary Investigation of Rivets and Riveted Joints in Metal Airplane Construction", "author": [ { "family_name": "Magden", "given_name": "John Leslie", "clpid": "Magden-John-Leslie" } ], "thesis_advisor": [ { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" }, { "family_name": "Sechler", "given_name": "Ernest Edwin", "clpid": "Sechler-E-E" } ], "thesis_committee": [ { "family_name": "Unknown", "given_name": "Unknown" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "No abstract.", "doi": "10.7907/MWT3-P557", "publication_date": "1934", "thesis_type": "masters", "thesis_year": "1934" }, { "id": "thesis:1394", "collection": "thesis", "collection_id": "1394", "cite_using_url": "https://resolver.caltech.edu/CaltechETD:etd-04152008-090606", "primary_object_url": { "basename": "Rassieur_wt_1934.pdf", "content": "final", "filesize": 5530203, "license": "other", "mime_type": "application/pdf", "url": "/1394/1/Rassieur_wt_1934.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "Hinge Moments", "author": [ { "family_name": "Rassieur", "given_name": "William Theodore", "clpid": "Rassieur-William-Theodore" } ], "thesis_advisor": [ { "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" } ], "thesis_committee": [ { "family_name": "Unknown", "given_name": "Unknown" } ], "local_group": [ { "literal": "GALCIT" }, { "literal": "div_eng" } ], "abstract": "The matter herein presented represents the results of an investigation on hinge moments of ailerons on a 1/12.5 scale model of a main wing airfoil of the XP3D-l Navy Patrol Boat.
\r\n\r\nThe data obtained were then employed in the calculation of stick forces due to aileron moments on the full scale airplane, the calculations covering a flying range of eighty to one hundred eighty miles per hour.
\r\n", "doi": "10.7907/5P3S-7022", "publication_date": "1934", "thesis_type": "masters", "thesis_year": "1934" }, { "id": "thesis:16692", "collection": "thesis", "collection_id": "16692", "cite_using_url": "https://resolver.caltech.edu/CaltechTHESIS:09032024-215953826", "primary_object_url": { "basename": "Schubauer_GB_1930.pdf", "content": "final", "filesize": 22841467, "license": "other", "mime_type": "application/pdf", "url": "/16692/1/Schubauer_GB_1930.pdf", "version": "v2.0.0" }, "type": "thesis", "title": "The Use of Mass Forces to Increase the Efficiency of Jet Propulsion", "author": [ { "family_name": "Schubauer", "given_name": "Galen Brandt", "clpid": "Schubauer-Galen-Brandt" } ], "thesis_advisor": [ { "family_name": "Millikan", "given_name": "Clark Blanchard", "clpid": "Millikan-C-B" }, { "family_name": "Klein", "given_name": "Arthur Louis", "clpid": "Klein-A-L" } ], "thesis_committee": [ { "family_name": "Unknown", "given_name": "Unknown" } ], "local_group": [ { "literal": "div_pma" } ], "abstract": "A scheme is suggested for increasing the efficiency of\r\njet propulsion by combining the jet with an airfoil. The\r\ncombination is called a jet-foil.
\r\n\r\nFrom a theoretical investigation of the jet when used in\r\nthis respect, it is concluded that high propulsive efficiencies\r\nare possible under ideal conditions since the action depends\r\nupon mass forces and is completely independent of viscosity.
\r\n\r\nExperimental determination of the forces on four model\r\njet-foils, made by measuring pressure distribution on the models:\r\nwhen placed in a wind stream, showed an increase in lift of the\r\nmodel with the jet compared to that of the model alone, and an\r\nincrease in drag for three of the models and a decrease for\r\nthe fourth. The lift and drag depended upon the strength of\r\nthe jet and upon the attitude of the model to the wind.
\r\n\r\nThe efficiency of the jet-foil is defined as that fraction\r\nof the unused power of the jet which the jet-foil absorbs\r\nby doing work. Zero efficiencies are obtained for the\r\nthree models showing increased drag, and values ranging from\r\n38 percent to zero for the fourth, which showed a decrease in\r\ndrag. A second set of efficiencies were calculated neglecting\r\nincreased drag. These range from 40 percent to zero and are\r\nmuch the same for all of the models, decreasing as the strength\r\nof the jet increases. An effort is made to account for the\r\nlow efficiencies on the basis of turbulence.
", "doi": "10.7907/2nf1-x409", "publication_date": "1930", "thesis_type": "masters", "thesis_year": "1930" } ]