STUDY OF DIFFERENCES BETWEEN REAL AND EFFECTIVE HEAT TRANSFER COEFFICIENTS TO PROVIDE CORRECT DATA ON TEMPERATURE FIELD CALCULATIONS AND COMPUTER SIMULATIONS DURING HARDENING OF STEEL
Journal Title: EUREKA: Physics and Engineering - Year 2018, Vol 0, Issue 3
Abstract
The paper analyses contemporary methods and probes for testing liquid media used as a quenchant in heat treating industry. It is shown that lumped-heat-capacity method, often used for testing liquid media, produces big errors during transient nucleate boiling processes due to incorrect calculation condition caused by use effective heat transfer coefficient (HTC). The effective heat transfer coefficients (HTCs), utilized for this purpose, are almost seven times less as compared with real HTCs that results in incorrect calculation the value of Bi. Instead of lumped-heat -capacity method, a general cooling rate equation is proposed for HTC calculation. It is underlined that effective HTCs can be used only for approximate core cooling rate and core cooling time of steel parts calculations. For investigation cooling capacity of liquid quenchants, including initial heat flux densities, HTCs and critical heat flux densities, high developed technique of solving inverse problem should be used based on accurate experimental data generated by testing liquid media with the Liscic/Petrofer probe or other similar technique.
Authors and Affiliations
Nikolai Kobasko
Keywords
Related Articles
- EP ID EP669023
- DOI 10.21303/2461-4262.2018.00646
- Views 169
- Downloads 0
RESEARCH OF MICROBIOLOGICAL INDICATORS OF QUALITY OF SURFACE WATERS OF NATURAL ENVIRONMENTAL TERRITORIES OF THE DANUBE BASIN
A comparative analysis of the sanitary and ecological state of surface watercourses in the upper part of the Danube basin (on theterritoryofUkraine) was carried out according to microbiological indicators. Similar hygien...
METHOD OF DETERMINING WEIGHTS OF TEMPORAL RULES IN MARKOV LOGIC NETWORK FOR BUILDING KNOWLEDGE BASE IN INFORMATION CONTROL SYSTEMS
The problem of constructing and expanding the temporal knowledge base for the information-control system is considered. This knowledge base is formally represented by the Markov logic network. It is shown that the behavi...
RATIONAL CHOICE OF TWO-SUPPORT SPINDLES FOR MACHINING CENTERS WITH LUBRICATION SYSTEM
In the multivariate design mode, based on the effective parallel design facilities, the rational choice of the design of the two-support spindle for the machining center is the main aim of this article. A modified scheme...
METHOD OF CONSTRUCTING AN ATTRIBUTE DESCRIPTION OF THE BUSINESS PROCESS "AS IS" IN THE PROCESS APPROACH TO ENTERPRISE MANAGEMENT
The problem of constructing an attribute description of a business process with the automated formation of process models “as is” using logs of information systems in which the tracks of individual processes are not iden...
PLASTICIFICATION OF LEATHER SEMIFINISHED CHROME TANNING USING BIOCATALITIC MODIFIER
The aim of the work is studying the plasticization process of semi-finished chrome tanning from hides of cattle for the production of elastic leather materials. The process of influence of biologically catalytic modifie...