Effect of periodic surface-potential variation on high-field tunneling in field-ionization processes
Field-ion microscope image formation, determining periodic surface potential variation effects on high field tunneling
Schrenk, G. L.↗
SEARCH · Engineering Papers
Results for “SCHRENK”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The electron transfer process in field ionization
Electron transfer in ion microscope field ionization, analyzing band and periodic surface structure effects, ionization probability and collision formalism
Fonash, S. J.↗
Caesium plasma diodes seeded with mercury or cadmium and the Penning effect
Cs plasma thermionic diode, using Penning effect for ionization rate increase via Hg or Cd seeding
Kaufman, A. J.↗
Optical analysis of Cassegrainian concentrator systems
Cone optics procedures have been developed to treat optical systems employing multiple reflectors. The objective of the procedures is to develop efficient techniques to treat multiple reflections of cones when the secondary reflecting surface is curved - in fact, curved differently in different directions. The particular optical system under consideration is the Cassegrainian Concentrator System - a system consisting of a paraboloidal primary reflector and a confocal hyperboloidal secondary reflector. Multiple reflection cone optics methodology as well as preliminary results for the flux distributions and intercept factors based on it are presented in this paper. It is shown that neglecting local curvature effects of the secondary reflector, i.e. even in the differential solid angle within the sun's cone, may overestimate the peak of the flux distribution at the receiver aperture by a factor of two or more.
Bass, A. H., Jr.↗
Aerodynamic computation of gliders
In the following discussion, a knowledge of the theoretical principles of airplane construction is assumed, as presented in detail by Vogt and Lippisch. A few quantities will however be otherwise designated, in accordance with the Gottingen symbols.
GLIDERS - DESIGN↗
Experiments with an Airfoil from which the Boundary Layer Is Removed by Suction
Our attempts to improve the properties of airfoils by removing the boundary layer by suction, go back to 1922. The object of the suction is chiefly to prevent the detachment of the boundary layer from the surface of the airfoil. At large angles of attack, such detachment prevents the attainment of the great lift promised by the theory, besides greatly increasing the drag, especially of thick airfoils. This report gives results of those experiments.
BOUNDARY LAYER REMOVAL - SUCTION↗
Effect of roughness on properties of airfoils
The first group of a large series of contemplated experiments on the effect of roughness was intended to show the effect of great roughness on airfoils of various sizes and attitudes.
AIRFOILS↗
Systematic investigation of Joukowsky wing sections
Ackeret began systematic polar measurements on Joukowsky wing sections, which were occasionally conducted in the wind tunnel. Under these conditions a considerable number of wing sections were tested during the last four years and the tests are now more or less concluded.
AIRFOILS - JOUKOWSKY - CHAR↗
Effects of roughness on airfoils
We will here report on the effects of coarsely roughening not only the pressure side but also the suction or upper side of airfoils, as the first group of a larger series of experiments.
AIRFOIL SURFACES - ROUGHNESS↗
Welding in airplane construction
The present article attempts to explain the principles for the production of a perfect weld and to throw light on the unexplained problems. Moreover, it is intended to elucidate the possibilities of testing the strength and reliability of welded parts.
WELDING↗
Calculation of Airplane Performances Without the Aid of Polar Diagrams
For good profiles the profile-drag coefficient is almost constant in the whole range which comes into consideration for practical flight. This is manifest in the consideration of the Gottingen airfoil tests and is confirmed by the investigations of the writer (measurements of the profile drag during flight by the Betz method), concerning which a detailed report will soon be published. The following deductions proceed from this fact. The formulas developed on the assumptions of a constant profile-drag coefficient afford an extensive insight into the influences exerted on flight performances by the structure of the airplane.
FORMULAS - PERFORMANCE↗
A few more mechanical-flight formulas without the aid of polar diagrams
The reliability of the assumption of a parabolic shape of the polar curve is investigated and found satisfactory for all practical purposes. It is further shown that the aerodynamically best possible or "ideal" airplane is produced on this assumption. Lastly, detailed suggestions are given on the possibilities of application of this method of calculation. It especially simplifies the design and evaluation of structural changes and the determination of the limits of technical possibilities. The present report deals only with the relations of the airfoils. The mutual action of the airfoils, engine and propeller will be treated in a subsequent report.
FORMULAS - PERFORMANCE↗
Materials and Methods of Construction in Light Structures
Different methods of constructing light airplanes are presented with a view toward increasing production and efficiency.
HUTTNER↗
Boundary layer removal by suction
Flight-test data and wind-tunnel data on suction profiles are substantially in agreement. The lift values found in the model test can be actually flown and used as a basis for the design. To visualize the action of the suction, the flow conditions with and without suction on the upper surface were photographed; figures 12 to 15 are sections of the film.
Schrenk, O↗
A simple approximation method for obtaining the spanwise lift distribution
The approximation method described makes possible lift-distribution computations in a few minutes. Comparison with an exact method shows satisfactory agreement. The method is of greater applicability than the exact method and includes also the important case of the wing with end plates.
Schrenk, O↗
Static longitudinal stability and longitudinal control of autogiro rotors
The present report discusses three different systems of elevator control and their effects on the stability and maneuverability of autogiros: (a) ailerons and elevators (standard); (b) blade control (la Cierval); (c) gravity control (new).
Schrenk, M↗
Model Experiments on the Forces and Moments Acting on an End Plate Fitted to a Wing
This paper reports on 4-component balance measurements with and without angle of sideslip made on an airfoil with end plate at one tip. In addition, pressure distribution measurements on the end plate served as a basis for the determination of the forces on the end plate and for the bending moments.
Schrenk, O↗
Experiments with suction-type wings
The present report collects the investigations of the past years which, while not as yet intended for use in construction, show different possibilities for the building of a suction-type wing and at the same time present some basic explanations concerning the problem of suction. Experiments and results with a thick wing profile are detailed as well as boundary layer removal by suction and sink action. Experiments with flap profiles are also included.
Schrenk, O↗