摘要 :
Aircraft travel has become a major form of transportation. Several of our major airports are operating near their capacity limit, increasing congestion and delays for travelers. As a result, the National Aeronautics and Space Admi...
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Aircraft travel has become a major form of transportation. Several of our major airports are operating near their capacity limit, increasing congestion and delays for travelers. As a result, the National Aeronautics and Space Administration (NASA) has been working in conjunction with the Federal Aviation Administration (FAA), airline operators, and the airline industry to increase airport capacity without sacrificing public safety. One solution to the problem is to increase the number of airports and build new. runways; yet, this solution is becoming increasingly difficult due to limited space. A better solution is to increase the production per runway. This solution increases the possibility that one aircraft will encounter the trailing wake of another aircraft. Hazardous wake vortex encounters occur when an aircraft encounters the wake produced by a heavier aircraft. This heavy-load aircraft produces high-intensity wake turbulence that redistributes the aerodynamic loads of trailing smaller aircraft. This situation is particularly hazardous for smaller aircraft during takeoffs and landings. In order to gain a better understanding of the wake-vortex/aircraft encounter phenomena, NASA Langley Research Center conducted a series of flight tests from 1995 through 1997. These tests were designed to gather data for the development a wake encounter and wake-measurement data set with the accompanying atmospheric state information. This data set is being compiled into a database that can be used by wake vortex researchers to compare with experimental and computational results. The purpose of this research is to derive and implement a procedure for calculating the wake-vortex/aircraft interaction portion of that database by using the data recorded during those flight tests. There were three objectives to this research. Initially, the wake-induced forces and moments from each flight were analyzed based on varying flap deflection angles. The flap setting alternated between 15 and 30 degrees while the separation distance remained constant. This examination was performed to determine if increases in flap deflection would increase or decrease the effects of the wake-induced forces and moments. Next, the wake-induced forces and moments from each flight were analyzed based on separation distances of 1-3 nautical miles. In this comparison, flap deflection was held constant at 30 degrees.
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摘要 :
A scheme of notation and nomenclature applicable to the dynamics and associated aerodynamics of both aeroplanes and missiles is proposed. The proposals are intended to supersede the attempts made, notably by Bryant and Gates, to r...
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A scheme of notation and nomenclature applicable to the dynamics and associated aerodynamics of both aeroplanes and missiles is proposed. The proposals are intended to supersede the attempts made, notably by Bryant and Gates, to revise and extend the existing standard reference in this field, namely R. & M. 1801.
Part 1 contains an extensive introduction describing the main objectives and summarizing a considerable amount of historical background. It also lists the symbols, references, and most of the tables for the whole report, and provides an index. All illustrations are appended to Part 1, and copies included in the remaining parts where required.
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A summary and critical review of available information on molecular quadrupole and higher moments is presented. A theorem is also proved which shows that only one independent scalar quantity is required to determine a molecular el...
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A summary and critical review of available information on molecular quadrupole and higher moments is presented. A theorem is also proved which shows that only one independent scalar quantity is required to determine a molecular electric multipole tensor of rank p for molecules with an n-fold axis of symmetry where p
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Normal forces, axial forces, pitching moments, and rolling moments on the model and hinge moments on each of the four control surfaces were measured. Control surfaces were deflected from -35 deg to 15 deg in various combinations t...
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Normal forces, axial forces, pitching moments, and rolling moments on the model and hinge moments on each of the four control surfaces were measured. Control surfaces were deflected from -35 deg to 15 deg in various combinations to produce pitching, yawing, and rolling moments on the model over a range of angles of attack from -5 deg to 25 deg at roll angles from -135 deg to 45 deg.
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This paper consists of a table of nuclear moments, accompanied by a discussion to enhance its usefulness. It is not a general review of the subject.
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The discussion on the electric dipole moment of neutrino is given. The manifestations of the electric dipole moment of neutrino and of its magnetic moment are practically indistinguishable in the case of massless or very light neu...
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The discussion on the electric dipole moment of neutrino is given. The manifestations of the electric dipole moment of neutrino and of its magnetic moment are practically indistinguishable in the case of massless or very light neutrino. 3 refs. (Atomindex citation 18:097199)
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The moments and product of inertia of the Fairey Delta 2 aircraft have been measured using the method of spring restrained oscillations. The moment of inertia results were satisfactory, but difficulty was found in determining the ...
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The moments and product of inertia of the Fairey Delta 2 aircraft have been measured using the method of spring restrained oscillations. The moment of inertia results were satisfactory, but difficulty was found in determining the product of inertia due to unsatisfactory design of the single point suspension rig.
A dependence of roll period on roll amplitude was discovered and this may be due to some form of ground effect. The damping in roll was found to vary with fuel state.
The agreement between the manufacturer's estimates and the measured moments and product of inertia was poor, and there is clearly a continuing need for inertia measurements. Simple estimates of the fuel inertias compared well with the measured values, agreement being within the expected accuracy of the measurements. The fuel load of the Fairey Delta 2 is relatively small, and simple estimates for greater loads might be less satisfactory.
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