Search results for "Pressure"

1989

Heat of crystallization significantly slows down polymer cooling and thus pressure drop increase during mould filling with thermoplastic crystalline polymers. If a correction of thermal diffusivity can account for such a cooling slow down at least as far as the effect on pressure drop is concerned, the use of nonisothermal crystallization kinetics may be avoided in the simulation of mould filling. A procedure to identify such a correction is outlined in this work. Pressure drop values during cavity filling calculated by using a corrected thermal diffusivity in the model proposed by Lord and Williams favourably compare with literature data taken with polypropylene and polyethylene resins. Be…

Two-phase flow of liquid–liquid mixture in the range of the water droplet pattern

2002

Abstract Phenomena accompanying flow of water–oil mixture during droplet flow of water in oil have been described. Aims used in the determination of characteristic parameters in two-phase liquid–liquid flow have been presented. The method for calculating the equivalent viscosity and pressure drop during flow of liquid–liquid mixture in the range of the water droplet pattern has been given.

CFD prediction of concentration polarization phenomena in spacer-filled channels for Reverse Electrodialysis

2014

Abstract Salinity Gradient Power generation through Reverse Electrodialysis (SGP-RE) is a promising technology to convert the chemical potential difference of a salinity gradient into electric energy. In SGP-RE systems, as in most membrane processes, concentration polarization phenomena may affect the theoretical driving force and thus the performance of the process. Operating conditions, including the feed solution flow rate and concentration and the channels׳ geometrical configuration, may greatly influence both the polarization effect and the pumping energy consumption. The present work uses CFD to investigate the dependence of concentration polarization and pressure drop on flow rate, f…

CFD Modelling of the Demister in the Multi Stage Flash Desalination plant

2011

Abstract Demisters are used to remove entrained brine droplets from flashed off vapor within the flashing stages of the multi stage flash desalination process (MSF). This is necessary to prevent accumulation of brine droplets on the outside surface of the condenser tubes and contamination of the desalinated water. The aim of this work is to design a new demister with lower pressure drop and unaffected separation efficiency which can be later installed in the flashing stages of the MSF plant and causes reduction in the required heat transfer area. In this work the demister performance is predicted as a function of design (wire diameter), and operating parameters (stage temperature). This obj…

Jet Engine Design Optimization Using a Knowledge-Based Master Model

2012

This paper presents a preliminary design optimization study of a jet engine structure using a knowledge-based master modeling approach. The objective function is derived based on input-output relationships of a cost-performance model, where specific fuel consumption, pressure loss and direct cost are considered. The advantage of this problem formulation is that it entails a single composite objective function that takes into account mass, structural characteristics, dynamic response and translates them to a direct operational cost function to be minimized. A fan-blade-off scenario is considered as the loading case in this paper. The loss of one fan blade during nominal operation causes a ro…

Steady state and transient thermal–hydraulic analyses on ITER divertor module

2005

Abstract One of the most challenging components of ITER is the divertor devoted at controlling the characteristics of the plasma boundary, exhausting the α particles and reducing the impurities in the plasma. The thermal–hydraulic design of the divertor is particularly, demanding because of the high heat loads and the cooling flow margin in the plasma-facing components (PFCs). The pressure drop is limited by the pumping power and also avoiding the risk of reaching critical heat flux (CHF). Furthermore, for maintenance operation foreseen, each single divertor cassette should be drained and dried before withdrawing it out from the vacuum vessel. To address these requirements, European Fusion …

Control of VOC emissions from a flexographic printing facility using an industrial biotrickling filter.

2011

The study of an industrial unit of biotrickling filter for the treatment of the exhaust gases of a flexographic facility was investigated over a 2-year period with the objective to meet the volatile organic compound (VOC) regulatory emission limits. Increasing the water flow rate from 2 to 40 m3 h−1 improved the performance of the process, meeting the VOC regulation when 40 m3 h−1 were used. An empty bed residence time (EBRT) of 36 s was used when the inlet air temperature was 18.7 °C, and an EBRT as low as 26 s was set when the inlet temperature was 26.8 °C. During this long-term operation, the pressure drop over the column of the bioreactor was completely controlled avoiding clogging prob…

Tobacco and health : the changing role of the media

2015

Podeu consultar la versió en català a: http://hdl.handle.net/2445/103102

Comparison of unconfined and confined unsaturated hydraulic conductivity

2007

Abstract The field tension infiltrometer (TI) and the laboratory unit hydraulic gradient (UHG) methods are widely applied to determine the near-saturated soil hydraulic conductivity, K . Comparison between the two methods is relevant given that they differ in the explored soil volume (undetached or detached) and in the flow process (unconfined or confined). The objective of this investigation was to compare unconfined and confined measurements of unsaturated hydraulic conductivity. Twenty TI experiments were conducted in a relatively coarse-textured soil having an appreciable hysteretic behavior by using two different dry-to-wet-to-dry (DTWTD) sequences of pressure head, h 0 , values that d…

0204: Proteome-wide sex-related differences in response to mouse thoracic aortic constriction: molecular bio-signature of failing hearts

2014

Chronic pressure overload (PO) induces pathological left ventricular hypertrophy (LVH) leading to congestive heart failure (HF). Over-expression of FKBP12.6 (FK506 binding protein (K)) in mice should prevent Ca2+-leak during diastole and may improve overall cardiac function. In order to decipher molecular mechanisms involved in thoracic aortic constriction (TAC)-induced cardiac remodelling and the influence of gender and genotype, we performed a proteomic analysis using 2D-DIGE, mass spectrometry and bioinformatics techniques to identify alterations in characteristic biological networks. Wild type (W) and K mice of both genders underwent TAC. Thirty days post-TAC, the altered cardiac remode…