Tests of the 5" HVAR Projectile with Fin and Ring Tails

This report covers tests of a 2-inch diameter model of the 5" HVAR Projectile, conducted at the Hydrodynamics Laboratory of the California Institute of Technology. This work was authorized by a letter dated January 31, 1944 from Dr. E. H. Colpitts, Chief of Section 6.1, Office of Scientific Research and Development. The purpose of the tests was to determine the performance of the projectile with the standard 4-fin tail, and to investigate possible changes in the proportion of the fins in order to better the performance or make a more compact design. This report also includes an extensive investigation of the performance of various fin and ring tails applied to this projectile, as well as to similar projectiles of different lengths. It is hoped that the data contained herein may be of use in the design of a variety of bullet-shaped projectiles having either ring or fin tails. The Water Tunnel tests apply only to the projectile moving at subsonic speeds, i.e., during the acceleration period. The attached appendix gives definitions of the terms used throughout the text, as well as other pertinent data

MK 13-1 Torpedo with Various Noses

This report covers model tests of the MK 13-1 Torpedo without shroud ring tail, conducted at the Hydraulic Machinery Laboratory of the California Institute of Technology. These tests were made at the request of Dr. E . H. Colpitts, Chief of Section 6.1, National Defense Research Committee, in a letter dated October 8, 1943, and were for the purpose of determining the performance of the torpedo with seven different types of nose design

Upholstered household furniture in the United States: A survey of current ownership and purchasing plans

This report presents highlights of the results of a telephone survey of U.S. households concerning their ownership, purchasing plans, and preferences regarding upholstered household furniture. The survey was conducted in October and November 1989, by the Survey Research Unit of the Social Science Research Center of the Mississippi Agricultural and Forestry Experiment Station. The SUl\u27Vey also included Canadian households, and subsequent reports will present results for Canada as well as statistical analyses of specific results for both countries. The sUl\u27vey was intended to help identify market potential for various items of upholstered household furniture, and the results are therefore not dependent on short-term economic conditions. The economic recession in the United States since the 1989 survey does not affect the validity of results; market potential becomes sup· pressed demand in an economic downturn

MK25 Torpedo Exhaust Gas Investigation

This report covers tests made on models of the Mk 25 Torpedo to determine the effect of gas discharged in the vicinity of a power-driven propeller. It also covers, briefly, tests made on a double exhaust pipe and a single exhaust pipe, both with the vertical rudder set at 10° port but without propeller. All of the above was authorized by Dr E. H. Colpitts, Chief of Section 6.1, NDRC, in a letter dated May 4, 1944. This report is the fourth supplement to the report, Section No. 6.1-sr207-1275. Memorandum Reports dated June 22, 1944, July 15, 1944, and September 29, 1944 have been issued giving preliminary results on the tests reported herein. Tests were made on models having a scale ratio of 11:21. However, all dimensions and data refer to the prototype unless otherwise noted. Gas discharges are expressed in per cent. These figures have been calculated with reference to the amount of gas discharged from the prototype when running at 40.5 knots. Allowances for temperature and composition of the exhaust gases have been made by calculating the exit velocity when the torpedo is running at 40.5 knots and 15 feet submergence, computing the ratio of this velocity to that of the torpedo, and then calculating the amount of air required by the model to obtain this velocity ratio when operating at the equivalent submergence. This criterion requires that a different rate of air flow be taken as the 100% amount for each torpedo velocity investigated. However, as in the prototype the mass rate of gas flow in the model is constant for any given water velocity, independent of the changes in the tunnel pressure (i.e. submergence). With this torpedo operating at the normal speed of 40.5 knots and a submergence of 15 feet, the cavitation parameter is calculated to be 0.67. The appendix to this report gives definitions of terms and other pertinent data

Water Tunnel Tests of the MK 25 Torpedo with Gas Exhaust Through a Horizontal Pipe

This report covers tests made on the MK 25 torpedo to determine the effect of gas discharged through a horizontal exhaust pipe. This report is supplemental to the report, Section No. 6.1-sr207-1275, which described teats with the gas discharged through a vertical fin. It was requested by Dr. E. H. Colpitts, Chief of Section 6.1 NDRC, in a letter dated May 4, 1944. The objective of both this and the former report is to examine the effects of discharging the turbine exhaust gases through the fin structure instead of through the propeller shafts. Since the feasibility of this new method of exhaust discharge is greatly dependent on the effect of the gas flow on the afterbody fin structure and propeller zone, both studies have been restricted to the observation and analysis of this flow. Determination of the effects of the discharge passages and gas stream on the hydrodynamic stability, rudder control, and propeller efficiency have been deferred. Pending the development of an exhaust passage having discharge characteristics that are not visibly unsatisfactory. Several different lengths of exhaust pipe were tested; also, runs were made for various values of velocity and submergence and different amounts of gas discharged. Photographs were taken to show the exhaust cavities created under the different conditions