14,429 research outputs found

    Lifting surface theory for a helicopter rotor in forward flight

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    A lifting surface theory was developed for a helicopter rotor in forward flight for compressible and incompressible flow. The method utilizes the concept of the linearized acceleration potential and makes use of the vortex lattice procedure. Calculations demonstrating the application of the method are given in terms of the lift distribution on a single rotor, a two-bladed rotor, and a rotor with swept-forward and swept-back tips. In addition, the lift on a rotor which is vibrating in a pitching mode at 4/rev is given. Compressibility effects and interference effects for a two-bladed rotor are discussed

    Lifting surface theory for a helicopter rotor in forward flight

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    A lifting surface theory has been developed for a helicopter rotor in forward flight for incompressible flow. The method utilized the concept of the linearized acceleration potential and make use of the vortex lattice procedures. Results in terms of lift coefficient slope for several forward flight conditions are given

    A study of longitudinal oscillations of propellant tanks and wave propagations in feed lines. Part V - Longitudinal oscillation of a propellant-filled flexible oblate spheroidal tank

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    Analytical method for determining axisymmetric longitudinal mode shapes and frequencies of incompressible and inviscid fluid in pressurized flexible oblate spheroidal propellant tan

    Four-part differential leukocyte count using μflow cytometer

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    This paper reports the four-part differential leukocyte count (DLC) of human blood using a MEMS microflow (μflow) cytometer. It is achieved with a two-color laser-induced fluorescence (LIF) detection scheme. Four types of leukocytes including neutrophils, eosinophils, lymphocytes and monocytes are identified in blood samples, which are stained by fluorescein isothiocyanate (FITC) and propidium iodide (PI). The DLC results show good correlation with the count from a commercial hematology analyzer. The whole system is also implemented into a portable instrument for space application

    A study of longitudinal oscillations of propellant tanks and wave propagations in feed lines. Part I - One-dimensional wave propagation in a feed line

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    Longitudinal oscillations of propellant tanks and wave propagations in feed lines with streaming flui

    Transport equation for 2D electron liquid under microwave radiation plus magnetic field and the Zero Resistance State

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    A general transport equation for the center of mass motion is constructed to study transports of electronic system under uniform magnetic field and microwave radiation. The equation is applied to study 2D electron system in the limit of weak disorder where negative resistance instability is observed when the radiation field is strong enough. A solution of the transport equation with spontaneous AC current is proposed to explain the experimentally observed Radiation-Induced Zero Resistance State.Comment: 9 pages, 1 figur
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