A computational study of the installation effects in Coriolis flowmeters positioned downstream of different flow disturbance elements (a single elbow, closely coupled double elbows out-of-plane and an orifice) is presented. The mass-flow sensitivities are estimated using the results of a fully three-dimensional, coupled and partitioned numerical model that accounts for the fluid-structure interactions. The results show that the mass-flow sensitivity can vary for different circumferential positions of the motion sensors in a straight-tube full-bore meter. Because of flow splitters and the averaging of the response of both measuring tubes, the installation effects are reduced in a twin-tube design.

Response of turbine flow meter in a vertical air-water two-phase flow is experimentally investigated. The flow field and the transient response of turbine are captured through a high speed camera, and the cross-sectional phase distribution is recorded by arrayed ERT. The experiment reveals that the rotational rate of the turbine drops when air intrudes into the rotor, and the relative fluctuation amplitude of the rotation decreases with the water flow. For the benefit of combined flow measurement with ERT and turbine meter, an extension to TG turbine performance model involving the non-steady two-phase effects is implemented. It is found that, given the ERT phase information, the extended model may well depict the response of turbine flowmeter in two-phase vertical flow.

The article presents the results of tests carried out in turbine meters to investigate the effects of different viscosities in the curves, and to explore mathematical ways to express the low flow rate part of the curves in order to use them as a functional part of the flow meter curve, with some loss of uncertainty, but even so useful in a number of cases. The turbine meters have diameters of 25 mm, 40 mm and 50 mm, and the tests were carried out with three different viscosities of fluids (7cSt, 17cSt and 34cSt).

Ultrasonic flow metering with clamp-on type transducers is a promising method when portability in flow metering is necessary. Nevertheless, the clamp-on ultrasonic flow meter has low measurement accuracy as flow speed in the pipe decreases. If the two types of clamp-on ultrasonic flow paths, namely, Z-shaped and V-shaped ultrasonic paths, are combined, measurement accuracy can be increased because the metering output becomes robust. In the present study, the measurement accuracy of the combined clamp-on ultrasonic flow meter was within ±2 % at 50 m³/h, which was smaller than those of the Z-shaped and the V-shaped clamp-on ultrasonic flow meters at the same flow rate. This can provide an advantage for water resource management because a general guideline for the water resource management is less than ±2 %.

There are benefits, limitations and trade-offs to be taken in to account when considering using a flow conditioner with an ultrasonic meter. These include aspects such as the pressure loss, the risk of fouling and the influence on meter repeatability, as well as the ease and reproducibility of manufacturing. This paper discusses different flow conditioner designs and introduces a new design intended for use with 4-path ultrasonic flowmeters. Performance data and permanent pressure loss measurements are presented and compared with a commonly used form of perforated plate flow conditioner. It is shown that comparable flowmeter performance can be achieved while reducing the pressure loss significantly.