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The Laser differential Doppler technique has a high resolution power of space and time and it won't touch and disturb the object of measuring in the measurement of the velocity of flow,as a result of this, it isapplied widely in the research in the tube linear flow and its transtion region and the velocity in boundarylayer. This essay deals with the using of two Dove prisms with their basal planes mirrored half transparent and half reflectional glued togather as a light splitting element. The angle between two coherent light beamscan be made continously adjustable by changing the distance between the incident light beam and the gluingsurface. therefore, this can be applied to the measuring of different rate of flow. After using this device forthe actual measurement of the velocity constant flow,the experimental curve which is among 0, the angle be.tween two coherent light beams and V,the velocity of flow and Doppler ferqency slight is obtained. Be-cause this curve differs slightly from the theoretical value ,the reason why there exists such a difference is al-so explained later in the essay.1. |
