Pressure Drop in Capsule Transporting Bends Carrying Spherical Capsules

One of the most important parameters in designing a capsule transporting pipeline is the pressure drop in the pipes carrying capsules and associated pipe fittings such as bends etc. Capsules are hollow containers with typically cylindrical or spherical shapes flowing in the pipeline along with the carrier fluid. The dynamic behavior of a long train of capsules depends on the behavior of each capsule in the train and the hydrodynamic influence of one capsule on another. Researchers so far have used rather simplified empirical and semi-empirical correlations for pressure drop calculations, the range and application of which are fairly limited. Computational Fluid Dynamics (CFD) based techniques have been used to analyze the effect of the presence of solid phase in hydraulic bends. A steady state numerical solution has been obtained from the equations governing turbulent flow in pipe bends carrying spherical capsule train consisting of one to four capsules. The bends under consideration are of 45⁰ and 90⁰ with an inner diameter of 0.1m. The investigation was carried out in the practical range of 0.2 ≤Vb≥ 1.6 m/sec. The computationally obtained data set over a wide range of flow conditions has been used to develop a rigorous model for pressure drop calculations. The pressure drop along the pipe bends, in combination with the pressure drop along the pipes, can be used to calculate the pumping requirements and hence design of the system

Flow diagnosis in a domestic radiator

In UK, domestic heating contributes to about 40% of annual energy consumption. Effective and efficient heating systems are essential to drive the cost of heating down. Although there are several types of heating systems, radiators are the most popular heat emitters. Head loss in a radiator depends on various design parameters based on fluid flow path conditions and design of the radiator. In the present study, a computational fluid dynamics (CFD) code has been used to analyse flow distribution within a domestic radiator. For this study a radiator with dimensions of 300mm by 600mm with 18 columns has been considered. The study has been carried out on a radiator with BBOE and BTOE configuration at various flow rates. In this paper results are presented from a series of analysis in which flow structure within the radiator has been diagnosed

Optimisation of a capsule transporting pipeline carrying spherical capsules.

Pipelines carrying fluids and slurries are very common. The third-generation pipelines carrying spherical or cylindrical capsules (hollow containers) filled with minerals or other materials including hazardous liquids are rather a new concept. These pipelines need to be designed optimally for commercial viability. Researchers, so far, have used rather simplified empirical and semi-empirical methods for optimisation purposes, the range and application of which is fairly limited. This study uses a rigorous approach to predict pumping cost based on Computational Fluid Dynamics (CFD) analysis and hence optimise capsule pipelines. A numerical solution has been obtained for pressure drop from the equations governing the turbulent flow around a concentric spherical capsule train consisting of 1–4 equal density capsules in a hydraulically smooth pipe section. The diameter of the pipe used in the analysis is 0.1m while the capsules’ diameters are in the range of 50 to 80% of the pipe diameter. The investigation was carried out in the practical range of 0.4 [less than] bulk velocity [greater than] 1.6 m/sec. Obtained results of pressure gradient along the pipeline in presence of capsules were compared with the available experimental data to validate the model used. The results predicted by the model agree well with the experimental data. The computationally obtained data over a wide range of flow conditions has then been used to develop a rigorous model for pressure drop. The pressure drop along the pipe can be used to calculate the pumping requirements and hence design of the system. The least cost principle has been used for optimisation

Effects of a freely moving maintenance device on the hydrodynamic characteristics of pipe bends.

Regular inspection and maintenance of oil and gas pipelines is crucial for safe and cost effective operation of oil and gas industry. Various techniques are practised globally for this purpose. One such technique is to insert a maintenance device within the pipeline that can monitor and record various parameters of interest, such as corrosion etc., for in-situ inspection and repair of the pipeline. The shape of maintenance device is conventionally rectangular and it houses different sensors to monitor pipeline condition. The maintenance device are thus hollow and can propagate freely within the pipeline. Extensive research has been carried out on the use and effects of such maintenance devices in straight pipes, however, published literature regarding their use in pipe bends is severely limited. In the present study, an advanced numerical approach has been used to investigate the effects of the presence of a maintenance device on the flow structure and hydrodynamic characteristics of hydraulic pipe bends used within oil and gas sector. A novel methodology has been used, and verified, to predict the velocity of the maintenance device within pipe bends. It has been observed that after the maintenance device is inserted in a pipe bend, the flow structure within the bend changes significantly. The flow within the bend has been noticed to become highly non-uniform, with the generation of considerable amount of secondary flows. This leads to substantial increase in the pressure drop across the bends. This information can be integrated in the pipeline design for better accuracy

Effect of surface roughness on the aerodynamic performance of an articulated truck-trailer assembly.

Aerodynamic drag is the most dominant resistive force to the motion of a vehicle, several methods of drag reduction have been applied over the years; these mainly include shape modification and add-on devices. A novel method to improve drag response of a truck is to modify the flow so that the flow remains uniformly attached to the vehicle. This will result in a smaller wake of the vehicle and consequently reduces drag. The present study investigates the feasibility of employing one such flow modifying technique. Surface roughness has been systematically introduced on the tractor-trailer unit in the form of spherical-shaped structures and the drag of the vehicle has been measured. Computational Fluid Dynamics (CFD) based techniques have been employed to numerically simulate the flow of air over the tractor-trailer unit. The results show that the surface roughness parameters affect the overall fluid flow around the truck-trailer unit, and hence have a significant effect on the aerodynamic drag force of the vehicle. Drag force has been observed to increase by 1% when valleys were introduced as surface roughness. However, drag reduction of 1.9% has been recorded in case of roughness peaks. The results suggest that although the peaks act as a restriction to the local flow, they contribute more towards reducing the overall drag. In case of the roughness valleys, the drag force increases because these valleys introduce more non-uniformity in the flow without any benefit in drag reduction

Comparison of operational effectiveness of a turbocharger volute.

Centrifugal compressors are commonly used across a wide range of applications such as in the automotive industry for engine turbocharging. A turbocharger has four main components i.e. inducer, impeller, diffuser and volute. Turbocharger volutes are commonly designed by neglecting the effects of friction, however, in the real-world, frictional effects have a significant influence on the performance and efficiency of the volute and the turbocharger. This study focuses on the operational effectiveness of the turbocharger volute, making use of two asymmetric type volute models that have been designed for high-pressure centrifugal compressors. For this purpose, advanced Computational Fluid Dynamics (CFD) based techniques have been employed. Three dimensional models of the turbocharger compressor stage have been developed and analysed by monitoring the pressure fluctuations through the volutes. Incorporating frictional effects has been noticed to have prominent influence downstream of the tongue, in the tail of the turbocharger compressor volute. This study shows that designing the turbocharger volute, by overlooking the frictional effects, results in an overestimation of the pressure fluctuations observed within the volute. Therefore, from an operations perspective, it is beneficial to design the volute incorporating frictional effects for high-pressure centrifugal compressor applications

Effect of the Shape of Stator Blades on the Performance Output of a Vertical Axis Marine Current Turbine

Due to the diminishing reserves of fossil fuels and increased pollution from exploitation of these fuels, the world is focusing on the renewable energy sources. Energy from tidal waves is one of the most exciting forms of renewable energy because of its consistent nature. Hence, the predictable, consistent and reliable nature of marine currents has enthused the researchers to emphasize on harnessing energy from marine currents in order to meet the renewable energy targets. Exploitation of this technology is underway and further research is required to extract this energy optimally. Operating under water and harnessing kinetic energy has restated the importance of Vertical Axis Marine Current Turbines (VAMCTs). Recent studies have shown that the shape of the blades, within a VAMCT, has an appreciably considerable effect on its performance output. The flow field in the vicinity of the VAMCT is greatly affected by the design and shape of the stator blades. This paper presents an effort carried out to analyze the effect of the shape of the stator blades of a VAMCT on its performance output. VAMCT with curved stator blades has been analyzed and the results have been compared with the existing literature for the performance output from a VAMCT having straight stator blades. It has been shown that a VAMCT with curved stator blades performances superiorly as compared to straight stator blades. Furthermore, the operational range of a VAMCT with curved stator blades increases significantly as compared to straight stator blades

Optimal Design of Capsule Transporting Pipeline carrying Spherical Capsules

A capsule pipeline transports material or cargo in capsules propelled by fluid flowing through a pipeline. The cargo may either be contained in capsules (such as wheat enclosed inside sealed cylindrical containers), or may itself be the capsules (such as coal compressed into the shape of a cylinder or sphere). As the concept of capsule transportation is relatively new, the capsule pipelines need to be designed optimally for commercial viability. An optimal design of such a pipeline would have minimum pressure drop due to the presence of the solid medium in the pipeline, which corresponds to minimum head loss and hence minimum pumping power required to drive the capsules and the transporting fluid. The total cost for the manufacturing and maintenance of such pipelines is yet another important variable that needs to be considered for the widespread commercial acceptance of capsule transporting pipelines. To address this, the optimisation technique presented here is based on the least-cost principle. Pressure drop relationships have been incorporated to calculate the pumping requirements for the system. The maintenance and manufacturing costs have been computed separately to analyse their effects on the optimisation process. A design example has been included to show the usage of the model presented. The results indicate that for a specific throughput, there exists an optimum diameter of the pipeline for which the total cost for the piping system is at its minimum

A Study on Optimal Sizing of Pipeline Transporting Equi-sized Particulate Solid-Liquid Mixture

Pipelines transporting solid-liquid mixtures are of practical interest to the oil and pipe industry throughout the world. Such pipelines are known as slurry pipelines where the solid medium of the flow is commonly known as slurry. The optimal designing of such pipelines is of commercial interests for their widespread acceptance. A methodology has been evolved for the optimal sizing of a pipeline transporting solid-liquid mixture. Least cost principle has been used in sizing such pipelines, which involves the determination of pipe diameter corresponding to the minimum cost for given solid throughput. The detailed analysis with regard to transportation of slurry having solids of uniformly graded particles size has been included. The proposed methodology can be used for designing a pipeline for transporting any solid material for different solid throughput

Effect of the Length and Diameter of a Cylindrical Capsule on the Pressure Drop in a Horizontal Pipeline

Capsule pipeline research involves the study of the flow in a pipe of a long train of spherical or cylindrical capsules (hollow containers) filled with minerals or other materials including hazardous liquids. The behavior of the capsule train will depend upon the behavior of each capsule in the train and the hydrodynamic influence of one capsule on another. Designers are in need of a general correlation to calculate pressure drop in a capsule pipeline. Researchers, so far, have used rather simplified empirical and semi-empirical correlations for pressure drop calculations, the range and application of which is fairly limited. A mathematical correlation developed for pressure drop in cylindrical capsule of equi-density as its carrying medium is presented here. Based on Computational Fluid Dynamics (CFD) a numerical solution has been obtained from the equations governing the turbulent flow around a concentric cylindrical capsule in a hydraulically smooth pipe section. The diameter of the pipe used in present study is 0.1m while that of capsules are in the range of 50–80% of the pipe diameter. The investigation was carried out in the practical range of 0.2 ≤Vb≥ 1.6 m/sec. The computationally obtained data set over a wide range of flow conditions have then been used to develop a rigorous model for pressure drop. Using this model the pressure drop along the pipeline can be computed which then can be used to calculate pumping requirements