Utveckling av en metod och en utrustning för mätning av bränslesprayers rörelsemängd

Sammanfattning: A new type of device for measuring the v m& –rate of fuel sprays from a diesel fuel injector has been developed and the various steps in the development are described. The device works by deflecting all of the sprays from the injector at the same time by using a bell shaped deflector. A load cell consisting of a machined steel part with strain gauges mounted on it measures the resulting force. The shape of the curvature in the deflector bell shape has been evaluated by photographing the flow in a 2D–version of the curve shape. A factor for compensation of the friction losses caused by the fuel flowing along a curved surface has been determined from an estimation of velocity loss based on these 2D flow visualizations. Care has been taken in the design of the parts to make the natural frequencies as high as possible and a damped suspension isolating the load cell from the injector holder has been developed. Methods for transforming the output signals of the device into an v m& – rate have been developed. The equipment has been found to function well for being the first version of a new measuring concept. Comprehensive suggestions about possible improvements for an updated version have been made based on experiences from the development and use of this device.