Hydrogas-dynamic exploration of the gas-liquid mixture flow in vertical lifting

The hydrodynamic flow of gas-liquid mixture was investigated in the vertical pipeline. It is confirmed by the existing experiment in technical references that to obtain theoretical work, taking into account B.A. Arkhangelsky`s theoretical basis dependence γfix/γl of friction is necessary. A new pressure gradient model tested in a great number of wells was chosen as well. Pressure losses for liquid and gas mediums are calculated by the Blazius formula, where the components in the mixture move in turbulent regime. The accuracy of the dependencies was verified using A.P Krylov`s experimental dependencies. A calculation method differ from A.P. Krylov`s has been developed. Via proposed method it was defined that each regime has its specific pressure gradient and there cannot be constant gradient for various regimes as A.P. Krylov shows.

Identifying the Impact of Concrete Specimens Size and Shape on Compressive Strength: A Case Study of Mud Concrete

Mud is a versatile material with a prodigious interest for traditional wall construction such as wattle and daub or rammed earth, with and without reinforcements. Mud concrete has been identified as a unique modern material, though more research is required for generalization. Compressive strength, a measure of concrete quality usually depends on the specimen’s size and shape. Specimen’s size and shape for mud concrete is yet to be identified and established. Addressing this knowledge gap, this research aims at investigating the effect of specimen’s size and shape on the compressive strength of mud concrete. At first, the compressive strength’s variation was estimated by varying water content. Then, the water content was kept constant and the variations of compressive strength were estimated by varying specimen size and shape. Both experiments were conducted for different mixtures and percentages of cement. The initial results suggest that the compressive strength of mud concrete decreases with the increase of water content. The decrease indicated linear behavior with a constant gradient. Less influence on compressive strength was observed by considering specimen size, while the shape showed more contribution. The effect of specimen size and shape was increased with the increase of compressive strength.

Determination of the Location and Magnetic Moment of Ferromagnetic Objects Based on the Analysis of Magnetovision Measurements

This article is concerned with the localization of ferromagnetic objects on the basis of magnetovision measurement analysis. In the presented case, the concept of localization is understood as the indication of the x, y, and z coordinates of the magnetic moment of the sought object. Magnetovision measurement provides a much simpler, two-dimensional localization of magnetic anomalies compared to existing active and passive mobile devices, largely based on operator knowledge and experience. In addition, the analysis of the obtained magnetovision measurement, by fusing data with a mathematical model, enables a quantitative assessment of the position of an object in space and the determination of the value and spatial orientation of its magnetic moment vector. The detection and localization method was verified using the certified magnetic moment standard. An additional novelty is the inclusion of the influence of the constant gradient of the external field in the model, which corresponds to disturbing the measurement by the influence of large, but distant, objects. The proposed three-dimensional magnetovision measurement method and its analysis enable the determination of the x, y, and z coordinates; the angular position; and the magnetic moment values of unknown magnetic dipoles in real conditions (effects of disturbances generated by other distant objects and background noise), thus precisely detecting and locating the ferromagnetic object.

The Weakest Point Evaluation Method for the Control Range of the Sound Velocity Profile Station

Sound velocity measurement is an important part of multi-beam sounding, and its accuracy directly affects the coordinate reduction of sounding points. Because of the variability of seawater sound velocity in time and space, the layout density of acoustic section stations directly affects the accuracy of multi-beam sounding. Over-dense layout wastes resources and causes inefficiency; over-sparse layout is not accurate enough to control the entire survey area. Based on the constant gradient acoustic ray tracing algorithm, this paper constructs the accuracy evaluation model of the weakest water depth point of acoustic profile station control, and analyses whether the existing multi-beam acoustic profile station layout scheme can satisfy the accuracy requirements of multi-beam sounding through an example calculation, which provides a theoretical basis for adjusting the layout scheme of acoustic profile station for field surveyors.