Experimental data and correlation results for the partitioning of 2,5-hexanediol and 2,5-hexanedione to high-pressure liquid phases of the (ethene+water+2-propanol) system

2007 ◽  
Vol 41 (2) ◽  
pp. 227-237 ◽  
Author(s):  
Jörg Freitag ◽  
Dirk Tuma ◽  
Gerd Maurer
2006 ◽  
Vol 503-504 ◽  
pp. 433-438 ◽  
Author(s):  
Xavier Sauvage

Concentration gradients resulting from long range diffusion during Severe Plastic Deformation (SPD) have been investigated with the 3D Atom Probe technique (3D-AP). First, in a pearlitic steel where alloying elements (Mn, Si and Cr) are partitioned between the ferrite and carbides in the non-deformed state. After processing by High Pressure Torsion (HPT), they are homogeneously distributed in the nanostructure, indicating that long range diffusion occurred along with the dissolution of carbides. 3D-AP data of a Cu-Fe composite processed by HPT show as well a significant interdiffusion of Cu and Fe, probably promoted by additional vacancies. On the basis of these experimental data, and using the theory described for irradiated materials, vacancy fluxes and vacancy production rates were estimated assuming that new vacancies are continuously produced and eliminated on grain boundaries.


2017 ◽  
Vol 2017 ◽  
pp. 1-15
Author(s):  
Salah Al-Enezi

This paper examines the effect of high-pressure carbon dioxide on the foaming process in polystyrene near the glass transition temperature and the foaming was studied using cylindrical high-pressure view cell with two optical windows. This technique has potential applications in the shape foaming of polymers at lower temperatures, dye impregnation, and the foaming of polystyrene. Three sets of experiments were carried out at operating temperatures of 50, 70, and 100°C, each over a range of pressures from 24 to 120 bar. Foaming was not observed when the polymer was initially at conditions below Tg but was observed above Tg. The nucleation appeared to occur randomly leading to subsequent bubble growth from these sites, with maximum radius of 0.02–0.83 mm. Three models were applied on the foaming experimental data. Variable diffusivity and viscosity model (Model C) was applied to assess the experimental data with the WLF equation. The model shows very good agreement by using realistic parameter values. The expansion occurs by diffusion of a dissolved gas from the supersaturated polymer envelope into the bubble.


2019 ◽  
Vol 12 (01) ◽  
pp. 1850105 ◽  
Author(s):  
Hairui Sun ◽  
Pin Lv ◽  
Chao Wang ◽  
Yunxian Liu ◽  
Xiaopeng Jia ◽  
...  

A series of binary-doped CoSb3 with Te and Se/Sn bulk compounds Co4Sb[Formula: see text]TexSny/Sey ([Formula: see text] and 0.6, [Formula: see text] and 0.3), have been successfully prepared via a simple high pressure and high-temperature (HPHT) method. And, the influence of the doping elements on the microstructure of the samples synthesized under diverse pressures and the corresponding TE performance were studied in detail. Comparing with other preparation methods, the synthesis time of HPHT was acutely shortened. The obtained samples contain more grain boundaries, lattice disorder, dislocations and the possible “nanodot”, which have positive effect on reducing thermal conductivity. The experimental data indicate that the absolute values of Seebeck coefficient increases with pressure. What’s more, the thermal conductivities show a monotone decreasing trend as the synthesis pressure rises. The minimum value obtained is 1.93[Formula: see text]Wm[Formula: see text]K[Formula: see text] at normal temperature for Co4Sb[Formula: see text]Te[Formula: see text]Se[Formula: see text] prepared under 3[Formula: see text]GPa.


Author(s):  
Jong-Shang Liu ◽  
Mark C. Morris ◽  
Malak F. Malak ◽  
Randall M. Mathison ◽  
Michael G. Dunn

In order to have higher power to weight ratio and higher efficiency gas turbine engines, turbine inlet temperatures continue to rise. State-of-the-art turbine inlet temperatures now exceed the turbine rotor material capability. Accordingly, one of the best methods to protect turbine airfoil surfaces is to use film cooling on the airfoil external surfaces. In general, sizable amounts of expensive cooling flow delivered from the core compressor are used to cool the high temperature surfaces. That sizable cooling flow, on the order of 20% of the compressor core flow, adversely impacts the overall engine performance and hence the engine power density. With better understanding of the cooling flow and accurate prediction of the heat transfer distribution on airfoil surfaces, heat transfer designers can have a more efficient design to reduce the cooling flow needed for high temperature components and improve turbine efficiency. This in turn lowers the overall specific fuel consumption (SFC) for the engine. Accurate prediction of rotor metal temperature is also critical for calculations of cyclic thermal stress, oxidation, and component life. The utilization of three-dimensional computational fluid dynamics (3D CFD) codes for turbomachinery aerodynamic design and analysis is now a routine practice in the gas turbine industry. The accurate heat-transfer and metal-temperature prediction capability of any CFD code, however, remains challenging. This difficulty is primarily due to the complex flow environment of the high-pressure turbine, which features high speed rotating flow, coupling of internal and external unsteady flows, and film-cooled, heat transfer enhancement schemes. In this study, conjugate heat transfer (CHT) simulations are performed on a high-pressure cooled turbine stage, and the heat flux results at mid span are compared to experimental data obtained at The Ohio State University Gas Turbine Laboratory (OSUGTL). Due to the large difference in time scales between fluid and solid, the fluid domain is simulated as steady state while the solid domain is simulated as transient in CHT simulation. This paper compares the unsteady and transient results of the heat flux on a high-pressure cooled turbine rotor with measurements obtained at OSUGTL.


Author(s):  
Tommaso Bacci ◽  
Tommaso Lenzi ◽  
Alessio Picchi ◽  
Lorenzo Mazzei ◽  
Bruno Facchini

Modern lean burn aero-engine combustors make use of relevant swirl degrees for flame stabilization. Moreover, important temperature distortions are generated, in tangential and radial directions, due to discrete fuel injection and liner cooling flows respectively. At the same time, more efficient devices are employed for liner cooling and a less intense mixing with the mainstream occurs. As a result, aggressive swirl fields, high turbulence intensities, and strong hot streaks are achieved at the turbine inlet. In order to understand combustor-turbine flow field interactions, it is mandatory to collect reliable experimental data at representative flow conditions. While the separated effects of temperature, swirl, and turbulence on the first turbine stage have been widely investigated, reduced experimental data is available when it comes to consider all these factors together.In this perspective, an annular three-sector combustor simulator with fully cooled high pressure vanes has been designed and installed at the THT Lab of University of Florence. The test rig is equipped with three axial swirlers, effusion cooled liners, and six film cooled high pressure vanes passages, for a vortex-to-vane count ratio of 1:2. The relative clocking position between swirlers and vanes has been chosen in order to have the leading edge of the central NGV aligned with the central swirler. In order to generate representative conditions, a heated mainstream passes though the axial swirlers of the combustor simulator, while the effusion cooled liners are fed by air at ambient temperature. The resulting flow field exiting from the combustor simulator and approaching the cooled vane can be considered representative of a modern Lean Burn aero engine combustor with swirl angles above ±50 deg, turbulence intensities up to about 28% and maximum-to-minimum temperature ratio of about 1.25. With the final aim of investigating the hot streaks evolution through the cooled high pressure vane, the mean aerothermal field (temperature, pressure, and velocity fields) has been evaluated by means of a five-hole probe equipped with a thermocouple and traversed upstream and downstream of the NGV cascade.


Author(s):  
K Battle ◽  
G D T Carmichael ◽  
E Cresswell ◽  
D Morse ◽  
H Porter ◽  
...  

To satisfy a requirement within the high pressure pipework industry in the UK, PVE/10 of the British Standards Institution established a Working Party to produce recommendations on the design and application of gusseted or mitred bends. The ultimate conclusions of the Working Party were eventually published within Amendment AMD 3545 to BS 806 ‘Ferrous pipes and piping installations for and in connection with land boilers’. Prior to this amendment BS 806 provided only limited guidance on the design of such bends, based on rules derived from custom and practice. AMD 3545 provides more extensive guidance than previously, based on experimental data and analysis and provides guidance on pipework design. This paper describes the background to the amendment and provides most of the reasoning behind the conclusions drawn by the Working Party.


Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 267 ◽  
Author(s):  
Vincenzo Stagno ◽  
Veronica Stopponi ◽  
Yoshio Kono ◽  
Annalisa D’Arco ◽  
Stefano Lupi ◽  
...  

Understanding the viscosity of mantle-derived magmas is needed to model their migration mechanisms and ascent rate from the source rock to the surface. High pressure–temperature experimental data are now available on the viscosity of synthetic melts, pure carbonatitic to carbonate–silicate compositions, anhydrous basalts, dacites and rhyolites. However, the viscosity of volatile-bearing melilititic melts, among the most plausible carriers of deep carbon, has not been investigated. In this study, we experimentally determined the viscosity of synthetic liquids with ~31 and ~39 wt% SiO2, 1.60 and 1.42 wt% CO2 and 5.7 and 1 wt% H2O, respectively, at pressures from 1 to 4.7 GPa and temperatures between 1265 and 1755 °C, using the falling-sphere technique combined with in situ X-ray radiography. Our results show viscosities between 0.1044 and 2.1221 Pa·s, with a clear dependence on temperature and SiO2 content. The atomic structure of both melt compositions was also determined at high pressure and temperature, using in situ multi-angle energy-dispersive X-ray diffraction supported by ex situ microFTIR and microRaman spectroscopic measurements. Our results yield evidence that the T–T and T–O (T = Si,Al) interatomic distances of ultrabasic melts are higher than those for basaltic melts known from similar recent studies. Based on our experimental data, melilititic melts are expected to migrate at a rate ~from 2 to 57 km·yr−1 in the present-day or the Archaean mantle, respectively.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 694 ◽  
Author(s):  
Jacek Sawicki ◽  
Krzysztof Krupanek ◽  
Wojciech Stachurski ◽  
Victoria Buzalski

Low-pressure carburizing followed by high-pressure quenching in single-piece flow technology has shown good results in avoiding distortions. For better control of specimen quality in these processes, developing numerical simulations can be beneficial. However, there is no commercial software able to simulate distortion formation during gas quenching that considers the complex fluid flow field and heat transfer coefficient as a function of space and time. For this reason, this paper proposes an algorithm scheme that aims for more refined results. Based on the physical phenomena involved, a numerical scheme was divided into five modules: diffusion module, fluid module, thermal module, phase transformation module, and mechanical module. In order to validate the simulation, the results were compared with the experimental data. The outcomes showed that the average difference between the numerical and experimental data for distortions was 1.7% for the outer diameter and 12% for the inner diameter of the steel element. Numerical simulation also showed the differences between deformations in the inner and outer diameters as they appear in the experimental data. Therefore, a numerical model capable of simulating distortions in the steel elements during high-pressure gas quenching after low-pressure carburizing using a single-piece flow technology was obtained, whereupon the complex fluid flow and variation of the heat transfer coefficient was considered.


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