Influence of heat transfer and curing on the quality of pultruded composites. I: Experimental

2002 ◽  
Vol 23 (5) ◽  
pp. 947-956 ◽  
Author(s):  
Shoujie Li ◽  
Zhongman Ding ◽  
Liqun Xu ◽  
L. James Lee ◽  
Herbert Engelen
Keyword(s):  
Heat Transfer ◽  
Pultruded Composites

Heat Transfer Enhancement in Separation Process of Ethanol from Ethanol Water Mixture by Using Surfactants

2020 ◽  
pp. 9-14 ◽  
Author(s):  
Acharya Anil Ramchandra ◽  
R. Kadam ◽  
A. T. Pise
Keyword(s):  
Heat Transfer ◽  
Ammonium Chloride ◽  
Sodium Dodecyl ◽  
Water Mixture ◽  
Transfer Enhancement ◽  
Surface Tension Reduction ◽  
Surface Active Agents ◽  
Surface Active ◽  
Time Required

Here the investigations are done while distillation of ethanol-water mixture for separating ethanol from fermentation process. Focus is to study reduction in time required and hence saving in energy for the distillation process of ethanol-water mixture under the influence of surface-active agents (Surfactants). This novelty is from observation of these surfactants to enhance heat transfer rate because of surface tension reduction in aqueous solutions. SDS (Sodium Dodecyl Sulphate), NH4Cl (Ammonium Chloride) and SLBS (Sodium lauryl benzene sulphonate) surfactants in different concentration are experimented. The concentration of these surfactant is varied from 1700 ppm to 2800 ppm. This range is decided by observing critical micelle concentration of used surfactants. Results showed that time is reduced and hence energy consumption is also reduced. Results shown by NH4Cl are found to be more useful as it is ecofriendly surfactant which is not affecting ethanol-water mixture. Use of ammonium chloride as surfactant in distillation is actually useful to reduce energy without hampering the quality of process is the novelty of this work.

Transient Heat Transfer Simulation in Rapid Heat Cycle Molding with Electric Heating

2012 ◽  
Vol 497 ◽  
pp. 121-125
Author(s):  
Shao Fei Jiang ◽  
Yin Kong ◽  
Ji Quan Li ◽  
Guo Zhong Chai
Keyword(s):  
Heat Transfer ◽  
Injection Molding ◽  
Temperature Response ◽  
Electric Heating ◽  
High Quality ◽  
Heat Cycle ◽  
Heat Transfer Simulation ◽  
Plastic Injection ◽  
Plastic Products

The demand of high quality for plastic products has facilitated the development of Plastic Injection Molding Technology, many new sorts of methods were created to improve the surface quality of plastic products, such as Rapid Heat Cycle Molding. But the temperature response law hasn’t figured out yet, and the influence elements of this process haven’t been clear, which seriously delay the appliction of Rapid Heat Cycle Molding.

Build Direction Effects on Additively Manufactured Channels

2015 ◽  
Author(s):  
Jacob C. Snyder ◽  
Curtis K. Stimpson ◽  
Karen A. Thole ◽  
Dominic Mongillo
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Small Scale ◽  
Turbine Cooling ◽  
Gas Turbine Cooling ◽  
Gas Turbine Heat Transfer ◽  
Manufacturing Techniques ◽  
Traditional Manufacturing

With the advances of Direct Metal Laser Sintering (DMLS), also generically referred to as additive manufacturing, novel geometric features of internal channels for gas turbine cooling can be achieved beyond those features using traditional manufacturing techniques. There are many variables, however, in the DMLS process that affect the final quality of the part. Of most interest to gas turbine heat transfer designers are the roughness levels and tolerance levels that can be held for the internal channels. This study investigates the effect of DMLS build direction and channel shape on the pressure loss and heat transfer measurements of small scale channels. Results indicate that differences in pressure loss occur between the test cases with differing channel shapes and build directions, while little change is measured in heat transfer performance.

Jet emerging from an annular nozzle and impinging onto cylindrical cavity: Effect of jet velocity on flow structure and heat transfer rates

2008 ◽  
Vol 222 (6) ◽  
pp. 1021-1031 ◽  
Author(s):  
S Z Shuja ◽  
B S Yilbas ◽  
S M A Khan
Keyword(s):  
Heat Transfer ◽  
Flow Structure ◽  
Cylindrical Cavity ◽  
Substrate Material ◽  
Working Fluid ◽  
Cavity Surface ◽  
Annular Nozzle ◽  
Transfer Rates ◽  
Jet Velocity

In laser gas assisting processes, nozzles are used to accelerate the impinging gas and attain a proper flow structure to improve the quality of the end product. In this study, the jet emerging from an annular nozzle and impinging onto a cylindrical cavity is considered. The effects of jet velocity at nozzle exit onto the flow structure in the region of the cavity and heat transfer rates from the cavity surface are examined. To resemble the laser-produced cavity, the cavity wall temperature is kept elevated (almost the melting temperature of the substrate material). Reynolds stress turbulence model is exploited to account for the turbulence. In the simulations, four jet velocities, two outer angles of the annular nozzle, and two depths of the cylindrical cavity are employed while air is used for the working fluid. It is found that jet velocity has a significant effect on the heat transfer rates and skin friction, which is more pronounced with increasing cavity depths.

Numerical Solution of Heat Transfer for Single and Multi-Metal Pan

2011 ◽  
Vol 148-149 ◽  
pp. 227-231
Author(s):  
Behnam Nilforooshan Dardashti ◽  
Mohammad Reza Sedighi
Keyword(s):  
Heat Transfer ◽  
Hot Spots ◽  
Single Layer ◽  
Transient Behavior ◽  
Maximum Temperature ◽  
Composite Form ◽  
Grey Cast ◽  
Iron Iron ◽  
Copper Aluminum

The quantity and quality of heat transfer to food are important factors in cookware. They depend on temperature degree and Temperature Distribution (TD) on top surface of pan that is exposed to food. The heat is not uniformly spread over the pan so is appeared hot spots on the cooking surface. Using Multi-Layer Plate (MLP) causes regular TD on the top while bottom heated irregularly. Another significant properties in cookware is that how long it can stores heat and using non-reactive materials is another essentially consideration. In this study the main objective is to find the best structure (single or multi-layer) and the best metals to provide maximum temperature and uniform TD upside surface of pan and also analyzing transient behavior of used materials with goal of improving the thermal quality of pan to economize the energy. To achieve this aim were employed Finite Element Method (FEM). The analysis has been extended for Copper, Aluminum, Titanium, Stainless Steel in composite form and Grey cast iron, Iron, Carbon steel as single layer, we achieved the best TD on Cu/Ti MLP.

scholarly journals The thermal conductivity of prosthetic sockets and liners

2007 ◽  
Vol 31 (3) ◽  
pp. 292-299 ◽  
Author(s):  
G. K. Klute ◽  
G. I. Rowe ◽  
A. V. Mamishev ◽  
W. R. Ledoux
Keyword(s):  
Quality Of Life ◽  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Side Effects ◽  
Thermodynamic Properties ◽  
Temperature Differential ◽  
Thermal Discomfort ◽  
Skin Temperatures

Elevated stump skin temperatures and the accompanying thermal discomfort are side effects of prosthesis use that may reduce amputee quality of life, particularly in hot or humid surroundings. Lower skin temperatures might be achieved through more effective heat transfer in the prosthesis, a process governed in part by the thermal conductivity of the sock, liner, and socket layers. To assess the thermodynamic properties of currently available components, an instrument capable of measuring the heat flux across a regulated temperature differential was developed. Experimental results show that the thermal conductivity ranged from 0.085 – 0.266 W/m · °K for liner materials and from 0.148 – 0.150 W/m · °K for socket materials. The results of this study demonstrate that the prescription of typical multi-layer prostheses constructed with the higher thermal conductivity materials might reduce temperature-related discomfort in patients.

scholarly journals THE RESEARCH OF THE BASIC CHANNEL CONTROL PROCESS OF PETROLEUM DISTILLATION AND DEVELOPMENT OF DYNAMIC MODELS / PAGRINDINIŲ NAFTOS DISTILIAVIMO SISTEMOS KANALŲ VALDYMO PROCESŲ TYRIMAS IR DINAMINIŲ MODELIŲ SUDARYMAS

2013 ◽  
Vol 5 (2) ◽  
pp. 115-118
Author(s):  
Vitaliy Likhavitski
Keyword(s):  
Heat Transfer ◽  
Boiling Point ◽  
Dynamic Models ◽  
Control Process ◽  
Temperature Fluctuations ◽  
Feed Stock ◽  
Flow Heat ◽  
Channel Control ◽  
Object Of Control

As the object of control, the process of oil distillation in the atmospheric column is complex and multidimensional with interconnected controlled variables. These controlled variables are the outgoing indexes of the column – the quality of receivable hydrocarbon fractions, for assessment of which the boiling point for each product is used. The basic perturbation actions to the process are connected with the adjustment of quantity and the composition of feed stock supplied to the column and flow heat transfer change due to temperature fluctuation of feed stock, temperature fluctuations of external reflux and other factors. Santrauka Atmosferinės naftos distiliavimo talpyklos sistemos valdymas yra sudėtingas ir daugiamatis procesas. Jį sudaro tarpusavio ryšiais susieti kintamieji. Tai yra distiliavimo talpyklos parametrai – gautųjų angliavandenilio frakcijų kokybė, pagal kurią nustatoma kiekvieno produkto virimo temperatūra. Šio proceso sudėtingumas siejasi su skysčio, tiekiamo į talpyklą, srauto ir sudėties reguliavimu, srauto temperatūros perdavimo pokyčiais dėl tiekiamo skysčio temperatūros bei atgalinio srauto temperatūros svyravimo ir kitų veiksnių. Straipsnis anglų kalba.

Comparison of R410A Condensation Heat Transfer Performance on Three Horizontal Tubes

2017 ◽  
Author(s):  
Xu Chen ◽  
Xiaoqiang Hong ◽  
Wei Li ◽  
David J. Kukulka
Keyword(s):  
Heat Transfer ◽  
Mass Flux ◽  
Heat Transfer Performance ◽  
Smooth Tube ◽  
High Mass ◽  
Outer Diameter ◽  
Transfer Performance ◽  
Vapor Quality ◽  
Helical Angle

An experimental investigation of R410A condensation outside a horizontal smooth tube, a herringbone tube and a newly developed enhanced surface EHT tube has been conducted. The herringbone tube has a fin root diameter of 11.43 mm, a helical angle of 21.3 °, 48 fins with a fin height of 0.262 mm and an apex angle of 36 °, the EHT tube has an outer diameter of 11.5 mm with special structure, while the smooth tube has an outer diameter of 11.43 mm. Experiments were taken at a constant saturation temperature of 45 °C, a constant inlet vapor quality of 0.8 and a constant outlet vapor quality of 0.1; mass flux ranging from 5 kg/(m2.s) to 250 kg/(m2.s). Those tubes have different heat transfer performance at different mass flux. The EHT tube has the least heat transfer coefficient than the other two tubes at a low mass flux, while at a high mass flux, the enhanced tubes have a better heat transfer performance than the smooth tube. Heat transfer performance combined with pressure drop measurements reveal that the herringbone tube generally has a better heat transfer performance than the EHT tube, pointing out the herringbone is a wise choice for shell side condensation instead of the EHT tube. Characteristic analysis is made to account for various phenomena in this series of experiments.

Effects of Thermal Transfer Paper Performance on Transfer Quality

2014 ◽  
Vol 881-883 ◽  
pp. 1443-1446
Author(s):  
Da Wan
Keyword(s):  
Heat Transfer ◽  
Transfer Rate ◽  
Air Permeability ◽  
Ash Content ◽  
Color Transfer ◽  
Thermal Transfer ◽  
General Law ◽  
Practical Guidance ◽  
Selection Research

Four kinds of thermal transfer paper with different paper characteristics were chosen, main properties including absorbability, air permeability, roughness, whiteness, formation and ash content were tested. Same ink color pieces were printed on these samples through colour printer, then these ink color pieces were transferred onto the same fabric based on the magnetic heat press machine, contrasting color transfer rate, gloss, adhesion and other indicators, the general law of paper performance on transfer quality was discussed. Research shows absorbability, roughness and air permeability will directly affect the quality of thermal transfer quality. Lower roughness and absorbability as well as moderate permeability have a significant role to improve the heat transfer quality. The result offers a certain theoretical reference and practical guidance to the selection, research and development of thermal transfer paper.

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