Πλοήγηση ανά Συγγραφέα "Bontozoglou, V."
-
Air-water two-phase flow and heat transfer in a plate heat exchanger
Vlasogiannis, P.; Karagiannis, G.; Argyropoulos, P.; Bontozoglou, V. (2002)A plate heat exchanger is tested under two-phase flow conditions by using an air/water mixture as the cold stream. Visual observations recorded by a high-speed video camera lead to the construction of a flow regime map. ... -
Bound-state formation in interfacial turbulence: direct numerical simulations and theory
Pradas, M.; Kalliadasis, S.; Nguyen, P. K.; Bontozoglou, V. (2013)We examine pulse interaction and bound-state formation in interfacial turbulence using the problem of a falling liquid film as a model system. We perform direct numerical simulations (DNSs) of the full Navier-Stokes equations ... -
Bubble dynamics during degassing of liquids at microgravity conditions
Divinis, N.; Karapantsios, T. D.; de Bruijn, R.; Kostoglou, M.; Bontozoglou, V.; Legros, J. C. (2006)This work investigates the growth of bubbles generated in a liquid saturated with dissolved CO(2) when its temperature is rapidly and locally raised above the saturation value, still below the boiling point of the test ... -
Bubbles growing in supersaturated solutions at reduced gravity
Divinis, N.; Karapantsios, T. D.; Kostoglou, M.; Panoutsos, C. S.; Bontozoglou, V.; Michels, A. C.; Sneep, M. C.; De Bruijn, R.; Lotz, H. (2004)This work investigates bubbles growing in a liquid saturated with a dissolved gas when its temperature is locally raised above its saturation value, yet below boiling. Local supersaturation is realized by giving heat pulses ... -
Characterization of trapped hydrogen in exfoliation corroded aluminium alloy 2024
Charitidou, E.; Papapolymerou, G.; Haidemenopoulos, G. N.; Hasiotis, N.; Bontozoglou, V. (1999) -
Computer aided analysis of viscous film flow along an inclined wavy wall
Malamataris, N. A.; Bontozoglou, V. (1999)The steady, laminar flow of a Newtonian liquid along an inclined wavy wall is studied in a two-dimensional numerical experiment using the Galerkin finite element method. The dimensionless Navier-Stokes equations are solved ... -
Corrosion-induced hydrogen embrittlement in aluminum alloy 2024
Kamoutsi, H.; Haidemenopoulos, G. N.; Bontozoglou, V.; Pantelakis, S. (2006)The present paper focuses on the observed corrosion-induced embrittlement of alloy 2024 and tries to answer the key question on whether the observed embrittlement is attributed to hydrogen uptake and trapping in the material. ... -
Corrosion-induced hydrogen embrittlement in aluminum alloy 2024
Kamoutsi, H.; Haidemenopoulos, G. N.; Bontozoglou, V.; Pantelakis, S. (2005)Corrosion is a major concern to the structural integrity of aging aircraft structures. The effect of corrosion on the damage tolerance ability of advanced aluminum alloys calls for consideration of the problems associated ... -
Decolorization kinetics of Procion H-exl dyes from textile dyeing using Fenton-like reactions
Ntampegliotis, K.; Riga, A.; Karayannis, V.; Bontozoglou, V.; Papapolymerou, G. (2006)The decolorization kinetics of three commercially used Procion H-exl dyes was studied using a Fenton-like reagent. The effect of the major system parameters (pH, concentration of H2O2 and Fe3+ and initial dye concentration) ... -
Decomposition of NH3 on Pd and Ir - Comparison with Pt and Rh
Papapolymerou, G.; Bontozoglou, V. (1997)The unimolecular decompositions of NH3 on polycrystalline wires and foils of Pd and Ir are examined and compared with the corresponding ones on Pt and Ph. The reactions were carried out in a differential flow reactor, at ... -
Desalination by mechanical compression of humid air
Vlachogiannis, M.; Bontozoglou, V.; Georgalas, C.; Litinas, G. (1999)A novel desalination concept is described, combining the principles of humidification-dehumidification and mechanical vapor compression. Thermodynamic analysis indicates the effect of operating conditions on water production ... -
Effect of channel width on the primary instability of inclined film flow
Vlachogiannis, M.; Samandas, A.; Leontidis, V.; Bontozoglou, V. (2010)A procedure is developed to detect the onset of interfacial instability in inclined film flows (with estimated accuracy better than 5%) and is used to show that the finite width of experimental channels stabilizes the ... -
Effect of Fluid Properties on Flow Patterns in Two-Phase Gas Liquid Flow in Horizontal and Downward Pipes
Tzotzi, C.; Bontozoglou, V.; Andritsos, N.; Vlachogiannis, M. (2011)This paper investigates the effect of gas density and surface tension on flow pattern transitions in horizontal and near-horizontal pipes. Experiments were conducted at atmospheric conditions in a 12.75-m long pipe with a ... -
Effect of prior deformation and heat treatment on the corrosion-induced hydrogen trapping in aluminium alloy 2024
Kamoutsi, H.; Haidemenopoulos, G. N.; Bontozoglou, V.; Petroyiannis, P. V.; Pantelakis, S. (2014)The nature of the corrosion-induced hydrogen trapping in Al-alloy 2024-T351 was studied by thermal desorption spectroscopy. The microstructure was altered by solution treatment and plastic deformation, prior to corrosion. ... -
The effect of soluble surfactants on liquid film flow
Georgantaki, A.; Vlachogiannis, M.; Bontozoglou, V. (2012)We investigate experimentally the modifications in the dynamics of liquid film flow, resulting from the addition in water of the soluble surfactants iso-propanol (IP) and Sodium Dodecyl Sulfate (SDS). Recent experiments ... -
Evidence on the corrosion-induced hydrogen embrittlement of the 2024 aluminium alloy
Petroyiannis, P. V.; Kamoutsi, E.; Kermanidis, A. T.; Pantelakis, S. G.; Bontozoglou, V.; Haidemenopoulos, G. N. (2005)The present work aims to provide evidence of corrosion-induced hydrogen embrittlement of the aircraft aluminium alloy 2024. An extensive experimental investigation involving metallographic and fractographic analyses as ... -
Experimental evidence for a short-wave global mode in film flow along periodic corrugations
Cao, Z.; Vlachogiannis, M.; Bontozoglou, V. (2013)The primary instability of liquid film flow along periodically corrugated substrates is studied experimentally. Two different wall shapes, of the same wavelength and height, are tested for a wide range of inclinations. It ... -
Experimental investigation of the energy needs for a conventionally and an infrared (IR)-heated greenhouse
Kavga, A.; Panidis, Th; Alexopoulos, G.; Salahas, G.; Bontozoglou, V. (2011)The potential advantages of heating greenhouses by infrared (IR) heaters, instead of conventional hot air, are examined experimentally. Measurements of indoor and outdoor conditions during a typical cold night and whole ... -
Experimental Investigation of the Energy Needs for a Conventionally and an Infrared-Heated Greenhouse
Kavga, A.; Alexopoulos, G.; Bontozoglou, V.; Pantelakis, S.; Panidis, T. (2012)Infrared (IR) heating as alternative to forced air heating has been studied experimentally for 70 days in two identical, small-scale, experimental greenhouses. The two heating options were implemented with four IR electric ... -
Experimental study of inclined film flow along periodic corrugations: The effect of wall steepness
Argyriadi, K.; Vlachogiannis, M.; Bontozoglou, V. (2006)Gravity-driven film flow along an inclined periodic wall with transverse rectangular corrugations is studied experimentally. The effect of corrugation steepness (=height/length) is considered in detail and an interesting ...