ME 123 Venturi Lab Handout CEMS Home（我123文丘里实验室讲义河北回家）.pdfVIP

VENTURI LABORATORY ME 123: Mechanical Engineering Laboratory II: Fluids Dr. J. M. Meyers | Dr. D. G. Fletcher | Dr. Y. Dubief 1. Introduction In this experiment, we will study the laws of mechanical energy and mass conservation of an inviscid, incompressible fluid through Venturi flow. This will be done using pressure measurements made along Venturi apparatus inserted into the test section of a low-speed wind tunnel. A Venturi is a simple, yet elegant device that illustrates many fundamental fluid dynamic phenomena. We saw in class how the flow rate and velocity through a Venturi can be related to pressure measurements, using Bernoulli’s equation. Here we will explore the use of Bernoulli’s equation over a range of flow conditions, payin particular attention to the validity of the assumptions behind the derivation of Bernoulli’s equation. In particular, in deriving Bernoulli’s equation we assume that the flow in question is (A) inviscid, (B) steady, and (C) incompressible. The main objectives of this lab are to: • Learn how to perform standard air flow measurement using a wind tunnel. • Experimentally understand the concepts of mechanical energy conservation and mass flow conservation. • Compare reduced velocities for various area changes along the flow path of a Venturi insert using both Bernoulli and mass flow conservation relations. • Perform uncertainty analysis of reduced data and comment on the fidelity of both methods. 2. Experimental Arrangement The UVM Low Speed Wind Tunnel (Model Flotek 1440) will be the main experimental facility in this experiment. The test section cross section is listed at 12 in. x 12 in. but upon measuring, the values are actually closer to 11 7/8 in. x 11 7/8 in. (±1/8 in.). The wind tunnel uses a s