CHARACTERISATION OF MULTIPHASE FLUID-STRUCTURE INTERACTION USING NON-INTRUSIVE OPTICAL TECHNIQUES

The purpose of this study is to determine experimentally the effectiveness of passive drag reduction techniques (which involve adjusting surface geometry) within a chaotic multiphase flow system. To quantify the intrusion and disturbance caused, a liquid-air blast atomiser continuously discharges within a test section of air at atmospheric pressure, with a circular cylinder placed 25 cylinder diameters (250 mm) downstream of the nozzle. This cylinder is then replaced with other cylinders which have modified surface geometry. The data was obtained using Particle Image Velocimetry (PIV) and determines the fluid motion resulting from spray structure interaction of a liquid spray with a circular cylinder. Subtraction of non intruded spray images from intruded spray images at the same locations, using the time averaged analysis allows the direct comparison of the amount of disturbance each geometric variant has on the spray. Using this data alongside velocity profiles time averaged trends were compared. Drag reduction from V-shaped grooves provides the greatest disturbance reduction. This is due to the reduced shear stress around its cross section and the addition of small liquid eddies within each V-groove creates a gliding surface. These features proved to be most effective when monitoring drag reduction in multiphase flow-structure interaction

STUDY OF THE FILTRATION PROCESS THROUGH A CERAMIC CANDLE FILTER

ABSTRACT Ceramic candle filters have been developed for cleaning high-temperature high-pressure (HTHP) gas streams. They meet environmental and economical considerations in Combined cycle power plant, where gas turbine blades can be protected from the erosion that occurs due to using HTHP exhaust from the fluidized bed. Ceramic candle filters are the most promising hot gas filtration technology, which has demonstrated high collection efficiencies at high-temperature high-pressure conditions. This paper reports a computational fluid dynamics (CF)) investigation of a candle filter. Constant filtration velocity boundary models have been used to investigate the filter in cross flow conditions using the CFI) code FLUENT. Different approach (inlet) velocity to filter faze velocity ratios and different face velocities (ranging from 2 to 5 cm(s) are used in the CF) calculation. Particles in the diameter range 1 to 100 microns are tracked through the domain. The radius of convergence (or the critical trajectory) is compared and plotted as a function of many parameters. The deposition process and the factors that affect the build up of the filter cake have also been studied

The interaction of a cold atomised spray with a circular cylinder

The development of non-intrusive diagnostic techniques has significantly increased with the introduction of lasers. Laser based anemometry, such as Laser Doppler (LDA), Phase Doppler (PDA), and Particle Image Velocimetery (PIV) can provide an accurate description of flows without interference. This study determines experimentally the fluid motion resulting from the interaction of a liquid spray with a circular cylinder. Two experimental settings were examined: the first is a discharging spray into free air and the second is a spray impinging on a circular cylinder placed 25 cylinder diameters downstream of the nozzle. These sprays were quantified using PIV. A non-intrusive droplet sizing technique was used to characterise the spray. This has shown that, within the spray, the average droplet diameter increases when the circular cylinder is introduced and so does the frequency of occurrence of these large droplets. In the wake behind the cylinder, the smaller droplets were quickly entrained and recirculated, while the larger droplets continued in the general direction of the spray cone. © School of Engineering, Taylor's University College.Published versio

MIRTO: an open-source robotic platform for education

This paper introduces the MIddlesex RoboTic platfOrm (MIRTO), an open-source platform that has been used for teaching First Year Computer Science students since the academic year 2013/2014, with the aim of providing a physical manifestation of Software Engineering concepts that are often delivered using only abstract or synthetic case studies. In this paper we provide a detailed description of the platform, whose hardware specifications and software libraries are all released open source; we describe a number of teaching usages of the platform, report students’ projects, and evaluate some of its aspects in terms of effectiveness, usability, and maintenance

Photoinduced energy- and electron-transfer from a photoactive coordination cage to bound guests.

In a coordination cage which contains an array of twelve naphthyl chromophores surrounding a central cavity, photoinduced energy or electron-transfer can occur from the chromophore array to the bound guest in supramolecular host/guest complexes

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

THE INTERACTION OF LIQUID DROPS WITH A ROTATING GAS STREAM WITHIN A RAPIDLY REVOLVING ANNULAR ENCLOSURE

The flow phenomena occurring around a rotating shaft are extremely complex and are a common feature in turbomachinery such as the bearing chambers of aero engines. As the liquid jet impinges onto the shaft, circumferential streams of lubricating liquid droplets centrifuge away from the rotor surface and impinge onto the inner circumference of the stationary case. A further break-up of drops occurred whilst rotating around the shaft before impacting on to the casing surface. Non-intrusive laser techniques have been employed to aid the visualisation processes and the analysis of the flow phenomena occurring within the rotating annular enclosure. Results reveal that, the liquid flow conditions and the shaft rotation regimes, along with the aerodynamic movement of the air circulating around the shaft influence the dynamics of the droplets and consequently the lubrication processes within the bearing chambers