WorldCat Identities

Zalovcik, John A.

Overview
Works: 41 works in 61 publications in 1 language and 138 library holdings
Classifications: tl507,
Publication Timeline
Key
Publications about John A Zalovcik Publications about John A Zalovcik
Publications by John A Zalovcik Publications by John A Zalovcik
Most widely held works by John A Zalovcik
by ( Book )
3 editions published in in English and held by 53 libraries worldwide
by ( Book )
2 editions published in in English and held by 15 libraries worldwide
by ( Book )
2 editions published in in English and held by 9 libraries worldwide
by ( Book )
3 editions published between and 1995 in English and held by 3 libraries worldwide
Principles involved in the operation of stall-warning devices are described and conditions under which difficulty may be experienced are pointed out. Some specific examples of stall-warning devices are illustrated and described.
by ( Book )
3 editions published in in English and held by 3 libraries worldwide
Results of flight tests indicate that profile-drag coefficients which were obtained with the low-drag airfoils were lower than with the conventional types over the range of light coefficients tested. For comparable conditions of the lift coefficient and Reynolds Number, the low-drag airfoils have profile-drag coefficients which may be 27 percent lower than the profile drag of the conventional airfoils tested. Detailed results are presented graphically.
by ( Book )
3 editions published in in English and held by 3 libraries worldwide
Summary: Tests were made in high-speed dives and pull-outs to determine, by combined radar-optical tracking equipment, the static-pressure error of an airspeed-head installation on a P-51B airplane. The installation included a pitot-static head mounted on a boom 95 percent chord ahead of the leading edge of the wing near the tip. The tests were made in dives at flight Mach numbers up to 0.75 and included pull-outs up to 4g normal acceleration. The results indicated that the static-pressure error did not vary with Mach number by more than about 1 percent of the impact pressure over the range of conditions investigated.
by ( Book )
3 editions published in in English and held by 3 libraries worldwide
A boundary-layer-transition and profile-drag investigation was conducted in flight by the National Advisory Committee for Aeronautics on an experimental low-drag wing installed on a P-47 airplane designated the XP-47F and supplied by Army Air Forces. The wing incorporates airfoil sections that vary from an NACA 66(215)-215, a = 1.0 at the plane of symmetry to an NACA 67(215)-213, a = 7.0 at the tip. The surface of the wing as constructed was found to have such a degree of waviness that it had to be refinished in order to obtain the performance generally expected of low-drag airfoils. Measurements were made at a section outside the propeller slipstream with smooth and with standard camouflage surfaces and on the upper surface of a section in the propeller slipstream with the surface smoothed.
by ( Book )
3 editions published between and 1950 in English and held by 3 libraries worldwide
A method for calibrating the static-pressure source of a pitot-static airspeed installation on the airplane in level flight, dives, and other maneuvers is described. The method principally involves the use of radar-phototheodolite tracking equipmment and is particularly suited for higher speeds at high altitudes. The accuracy of the method is discussed and sample calibrations are included.
by ( Book )
2 editions published in in English and held by 3 libraries worldwide
by ( Book )
2 editions published in in English and held by 3 libraries worldwide
Summary: A flight investigation was made of boundary-layer and profile-drag characteristics of smooth wing sections of a P-47D airplane. Measurements were made at three stations on the wing: boundary-layer measurements were made on the upper surface of the left wing in the slip-stream at 25 percent semispan; pressure-distribution measurements were made on the upper surface of the left wing at 63 percent semispan; and wake surveys were made at 63 percent semispan of the right wing. The tests were made in straight flight and in turns over a range of conditions in which airplane lift coefficients from 0.15 to 0.68, Reynolds numbers from 7.7 x 10⁶ to 19.7 x 10⁶, and Mach numbers from 0.25 to 0.69 were obtained. The results of the investigation indicated a minimum profile-drag coefficient of 0.0062 for the smooth section at 63 percent semispan. At the highest Mach number attained in the tests, the critical Mach number was exceeded by at least 0.04 with no evidence of compressibility shock losses appearing in the form of increased width of the wake or increased profile-drag coefficient. For flight conditions approaching the critical Mach number, variations in Mach number of as much as 0.17 appeared to have no effect on the profile-drag coefficient. In the slipstream, transition occurred at least as far back as 20 percent chord on the upper surface at low lift coefficients.
by ( Book )
2 editions published in in English and held by 3 libraries worldwide
Summary: A flight investigation was made to compare static pressures in subsonic and supersonic flow over an airplane wing as measured by static-pressure tubes, a static-pressure belt, and orifices flush with the wing surface. The measurements were made on the upper surface of the wing of the P-47D airplane over a range of flight conditions in which local Mach numbers from 0.34 to 1.41 were obtained at the measurement stations. For some of the tests, a total-pressure tube was mounted on the wing surface to determine its characteristics in supersonic flow. The results indicated that static-pressure measurements obtained with suitably designed and installed flush orifices, static-pressure tubes, and static-pressure belt will be in reasonable agreement for both subsonic and supersonic flow. The pressures in supersonic flow measured by the total-pressure tube mounted on the wing surface were found to be in close agreement with values predicted by theory.
by ( Book )
2 editions published in in English and held by 2 libraries worldwide
Summary: Flight tests were made at high speeds with a P-47D airplane to determine the flow characteristics, as indicated by wool tufts, on a section of the upper surface of the wing. The behavior of the tufts, which were distributed over a section of the wing from 39.5 to 52.5 percent semispan, was determined from motion pictures. The tests were made in straight flight and in turns under conditions in which airplane lift coefficients from 0.10 to 0.54 and airplane Mach numbers from 0.58 to 0.78 were obtained. The results of the tests indicated that the flow remained smooth over the test panel until the critical Mach number of the panel was exceeded by 0.08 at a lift coefficient of 0.10 and by 0.05 at a lift coefficient of 0.50. Beyond these Mach numbers, the tufts indicated unsteadiness of flow and, finally, local separation when the Mach number exceeded the critical value by 0.13 at a lift coefficient of 0.10 and by 0.10 at a lift coefficient of 0.50. The region of separated flow originated in the neighborhood of 30 percent chord at high lift coefficients and 45 percent chord at low lift coefficients. Separation appeared to extend over not more than 15 percent chord.
by ( Book )
2 editions published in in English and held by 2 libraries worldwide
An investigation of the effectiveness of suction slots as a means of extending the laminar boundary layer has been made in flight at Reynolds numbers on an NACA 35-215 airfoil. The test panel, having a chord of 204 inches and an average span of 90 inches, was mounted on the left wing of a Douglas B-18-airplane provided for the tests by the Army Air Corps. The upper surface of the test panel was provided at first with nine spanwise slots and later with eight additional slots, all located between 20 and 60 percent of the chord.
by ( Book )
2 editions published in in English and held by 2 libraries worldwide
A flight investigation was made at high speeds to determine the profile drag of a P-47D airplane wing having production surfaces covered with camouflage paint. The profile drag of a wing section somewhat outboard of the flap was determined by means of wake surveys in tests made over a range of airplane lift coefficients from 0.06 to 0.69 and airplane Mach numbers from 0.25 to 0.78.
by ( Book )
1 edition published in in English and held by 2 libraries worldwide
by ( Book )
1 edition published in in English and held by 2 libraries worldwide
by ( Book )
1 edition published in in English and held by 1 library worldwide
A preliminary investigation was made to determine whether some characteristic of the boundary layer could be used to provide satisfactory warning of the increase in the stalling speed of a wing caused by ice formations on the leading edges. The tests were conducted with a Lockheed 12A low-wing, twin-engine, all-metal transport airplane. Wood strips were used to simulate the ice formations and total-pressure surveys were taken near the trailing edge behind the wooden strips as the airplane was stalled. Most of the stalls were made in level flight in the following conditions: (1) cruising, 80-percent rated power; (2) glide, power off, flaps retracted, landing gear up; and (3) approach, power off, flaps fully deflected, landing gear down. These flights were supplemented by a few stalls, in only the cruising condition, in which the airplane was banked to produce normal accelerations ranging from 1.2g to 1.6g.
by ( Book )
1 edition published in in English and held by 1 library worldwide
A flight investigation was made of boundary-layer and profile-drag characteristics of smooth wing sections of a P-47D airplane. In Mach range of 0.25 - 0.69, boundary-layer measurements were made on the upper wing surface at 25 percent semi-span, pressure-distribution measurements made on upper surface at 63 percent semi-span, and wake surveys made at 63 percent semi-span. The minimum profile-drag coefficient of 0.0062 was indicated for smooth section at 63 percent semi-span. Critical mach number was exceeded by 0.04, but no compressibility shocks appeared. In slipstream, boundary layer transition occurred as far back as 20 percent chord on upper surface at low lift coefficients.
by ( Book )
1 edition published in in English and held by 1 library worldwide
 
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English (61)