Experimental and Numerical Analysis of Multi-Hole Orifice Flow Meter: Investigation of the Relationship between Pressure Drop and Mass Flow Rate

The paper presents the results of the experimental and numerical analysis of a six-hole orifice flow meter. The experiments were performed on humid air in a 100 mm diameter duct. The aim of this research was to investigate the mass flow and pressure drop dependency in an orifice of a predetermined shape and to compare the results obtained with computational formulas recommended in the ISO 5167-2 standard for a single-hole orifice flow meter. The experiments and calculations were performed on several multi-hole orifice geometries with different contraction coefficient in a wide range of Reynolds numbers. The pressure was probed immediately upstream and downstream of the orifice. The flow coefficient determined for the six-hole orifice flow meter investigated was compared with the flow coefficient of conventional single-hole orifice with the same contraction coefficient. The results from computational formulas for single-hole orifice from ISO 5167 are also included in the paper. During some experiments, an obstacle has been introduced in the duct at variable distance upstream from the orifice. The effect of the thus generated velocity field disturbance on the measured pressure drop was then investigated. Numerical simulation of the flow with the presence of the obstacle was also performed and compared with experimental data.

Numerical Analysis of Fuel Injector Nozzle Geometry - Influence on Liquid Fuel Contraction Coefficient and Reynolds Number

This paper investigates the influence of the fuel injector nozzle geometry on the liquid fuel contraction coefficient and Reynolds number. The main three fuel injector nozzle geometry parameters: nozzle diameter (d), nozzle length (l) and nozzle inlet radius (r) have a strong influence on the liquid fuel contraction coefficient and Reynolds number. The variation of the nozzle geometry variables at different liquid fuel pressures, temperatures and injection rates was analyzed. The liquid fuel contraction coefficient and Reynolds number increase with an increase in the nozzle diameter, regardless of the fuel injection rate. An increase in the r/d ratio causes an increase in the fuel contraction coefficient, but the increase is not significant after r/d = 0.1. A nozzle length increase causes a decrease in the fuel contraction coefficient. Increase in the nozzle length of 0.5 mm causes an approximately similar decrease in the contraction coefficient at any fuel pressure and any nozzle length. Fuel injectors should operate with minimal possible nozzle lengths in order to obtain higher fuel contraction coefficients.

Experimental Study of Expansive Soil Improved by Lime

Expansive soil mixed with a certain amount of lime in the post-isostatic pressing, as measured through the oedometer specimen expansion and contraction coefficient changes. Test divided load and no-load charge plus two groups, drawn economically reasonable dosage of lime for building design and construction to provide evidence.

Thermodynamic model of the protector cooling system with applications

This paper presents thermodynamic model of the system for rubber strip (protector) cooling. This model is used for determining the number of cooling system cascades, and rubber contraction coefficient, important parameters in mechanical model of the system which is the starting point of designing control system for rubber strip cooling. The correlation between the working velocity and rubber strip dimension, as well as the relation for the cooling water flow per cascade is also given.

The Contraction Coefficient of a Free-Surface Flow Under Gravity Entering a Region Beneath a Semi-Infinite Plane

Borda's mouthpiece consists of a long straight tube projecting into a large vessel, where fluid enters the tube in a free surface flow that tends to become uniform far downstream in the tube. A two-dimensional approximation to this flow under gravity in the upper part of the tube leads to an evaluation of the contraction coefficient, the ratio of the constant depth of the uniform flow to the width of the tube. The analysis also applies to flow under gravity past a sluice gate, if the semi-infinite wall above the channel is rotated to the vertical. The contraction coefficient depends upon the Froude numberF, and is generally less than the zero gravity value of 1/2 that is approached asF→ ∞.