Search results for "Pressure drop"

Study on Interfacial Surface in Modified Spray Tower

2019

This paper presents an analysis of the changes in interfacial surface and the size of droplets formed in a spray tower. The interfacial surface and the size of droplets formed are of fundamental importance to the performance of the equipment, both in terms of pressure drop and process efficiency. Liquid film and droplet sizes were measured using a microphotography technique. The confusors studied were classical, with profiled inside surface, and with double profiled inside surface. The liquids studied were water and aqueous solutions of high-molecular polyacrylamide (PAA) of power-law characteristics. The ranges of process Reynolds number studied were as follows: ReG &isin

Simulazioni Numeriche del Campo di Moto e della Caduta di Pressione in Tubi Elicoidali

2009

Membrane Deformation and Its Effects on Flow and Mass Transfer in the Electromembrane Processes

2019

In the membrane processes, a trans-membrane pressure (TMP) may arise due to design features or operating conditions. In most applications, stacks for electrodialysis (ED) or reverse electrodialysis (RED) operate at low TMP (&lt

Pressure-Induced Deformation of Pillar-Type Profiled Membranes and Its Effects on Flow and Mass Transfer

2019

In electro-membrane processes, a pressure difference may arise between solutions flowing in alternate channels. This transmembrane pressure (TMP) causes a deformation of the membranes and of the fluid compartments. This, in turn, affects pressure losses and mass transfer rates with respect to undeformed conditions and may result in uneven flow rate and mass flux distributions. These phenomena were analyzed here for round pillar-type profiled membranes by integrated mechanical and fluid dynamics simulations. The analysis involved three steps: (1) A conservatively large value of TMP was imposed, and mechanical simulations were performed to identify the geometry with the minimum pillar density…

Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT

2014

Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (Delta P) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation Delta P. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of Delta P across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed Delta P was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coeffic…

Modelling flow and heat transfer in spacer-filled membrane distillation channels using open source CFD code

2013

Abstract A good understanding of the details of hydrodynamic and heat transport conditions and their impact on temperature polarisation and pressure drops is essential for optimum design of membrane distillation (MD) modules. To this end, the present work reports on initial progress in the development of a tool for 3D simulation of spacer-filled MD channels based on the open source CFD code library OpenFOAM. The paper discusses a number of modelling and implementation aspects including model geometry and computational domain, choice of boundary conditions, and discretisation schemes. The results pertaining to the effect of three different spacer types on the fluid dynamics and heat transfer…

Friction and Heat Transfer in Membrane Distillation Channels: An Experimental Study on Conventional and Novel Spacers

2022

The results of an experimental investigation on pressure drop and heat transfer in spacer-filled plane channels, which are representative of Membrane Distillation units, are presented and discussed. Local and mean heat transfer coefficients were obtained by using Thermochromic Liquid Crystals and Digital Image Processing. The performances of a novel spacer geometry, consisting of spheres that are connected by cylindrical rods, and are hereafter named spheres spacers, were compared with those of more conventional woven and overlapped spacers at equal values of the Reynolds number Re (in the range ~150 to ~2500), the pitch-to-channel height ratio, the flow attack angle and the thermal boundar…