SIMULTANEOUS MEASUREMENT OF FLOW SPEED DENSITY AND TURBULENCE BY THREE CURRENT METERS

摘要

PURPOSE:To make it possible to conduct simulaneous measurements of flow speed, vicosity, density and turbulence by a field test, by conducting numerical calculation on the basis of the Gauss-Newton law by using rotations measured by three current meters and a digital calulator. CONSTITUTION:A rotation of an impeller of a current meter in non-turbulent flow is to be N, and that in turbulent is to be NT. When a flow velocity is to be V, NT is to become N[1-CT/(V-AT)]. AT and CT are constants to be decided by degree of turbulence TF, and structure of the current meter is specially designed so that the constants are not affected by variations of dimensional values and physical values of the impeller. A density is to be rho, and a vector of X=(V,TF,rho) is to be introduced. The above equation is re-written to fn(X)= NTn-Nn[1-CTn/(V-ATn)], a value is sought by a calculatin in accordance with the Gauss-Newton law by using a microprocesser, and a calculation is continuosly executed starting from an itinial estimated value X0 until a real value X1 is obtained. This value gives approximations of V, TF, rho of the flow at the same time.