scholarly journals Prediction of the thermal bow of rotor based on the measured displacement and temperature

2020 ◽  
Vol 16 (10) ◽  
pp. 155014772096299
Author(s):  
He Peng ◽  
Zhaohua Zhou ◽  
Jigang Feng ◽  
Xiangyu Yu ◽  
Zhansheng Liu
Keyword(s):  
Polynomial Function ◽  
Primary Concern ◽  
Measured Temperature ◽  
Maximum Deflection ◽  
Cooling Process ◽  
Constraint Equations ◽  
Rotor Support ◽  
Measured Displacement ◽  
Forced Cooling ◽  
Thermal Deflection

The thermal bow of the rotor occurs in the cooling process after the shutdown of the aeroengine. The deflection of the bowed rotor is the primary concern of the research on this problem. The objective of this work is to propose a method to predict the bow shape of the rotor with the measured temperature and displacement in a rotor thermal bow experiment. The experiment was introduced and the variations of the measured temperature and displacement were analyzed. A series of polynomial function was proposed to model the bowed shape of the rotor. The measured temperature and displacement were taken into considered in the constraint equations, with which the coefficients in the polynomial function were obtained. The bow shapes of the rotor at different time in the experiments were analyzed. Results showed that the maximum deflection of the rotor was much greater than the measured displacement at the sections near the rotor support. The forced cooling could reduce the thermal deflection of the rotor quickly. The analysis of the different cases of experiment indicated that the proposed method could predict the bow shape of the rotor with the measured temperature and displacement.

Physical Modeling and Simulation of the Cooling-Down of Fused-Cast Refractories

2020 ◽  
Vol 996 ◽  
pp. 142-150
Author(s):  
Run Feng Wang ◽  
Ao Huang ◽  
Yan Zhu Huo ◽  
Li Jun Mei ◽  
Hong Jin Rao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Physical Simulation ◽  
Temperature Record ◽  
Measured Temperature ◽  
Interfacial Heat Transfer Coefficient ◽  
Interfacial Heat Transfer ◽  
Cooling Process

The accurate description of the interfacial heat transfer coefficient is of great significance for the accurate measurement of the temperature field in the process of casting cooling. In this paper, the solidification process of metallic tin in refractory mould was studied by physical simulation experiment, and the on-site temperature measurement of the mold structure was carried out. According to the temperature record, the numerical simulation method is used to realize the fitting of the calculated temperature and the measured temperature. The reversible method was used to calculate the interfacial heat transfer coefficient between the casting and the mould, and then the evolution of the internal temperature field of the casting during the cooling process was determined. The results show that the melt has a large shrinkage during the cooling process, and the interface heat transfer coefficient can reach 300 W·m-2·K-1, which provides a mathematical model for the annealing process of fused-cast refractories.

Thermal buckling of braided flax woven polylactic acid composites

2020 ◽  
pp. 073168442095774
Author(s):  
Sateeshkumar Kanakannavar ◽  
Jeyaraj Pitchaimani
Keyword(s):  
Polylactic Acid ◽  
Volume Fraction ◽  
Thermal Environment ◽  
Natural Fibre ◽  
Thermal Buckling ◽  
Maximum Deflection ◽  
Temperature Variations ◽  
Temperature Range ◽  
Set Up ◽  
Thermal Deflection

This study presents influence of thermal environment on buckling behaviour of natural fibre braided yarn fabric reinforced polylactic acid composite beams. The thermal buckling study is carried out using an in-house built experimental set up for beam like composites exposed to different types of in-plane temperature variations. Influences of temperature variations, direction of loading and volume fraction of fibre are studied in detail. Results indicate that deflection behaviour of natural fibre braided fabric/polylactic acid beam is entirely different from the polylactic acid beam. Enhancement of natural fibre braided fabric reinforcement on thermal deflection is observed only at higher temperature as less deflection is observed for polylactic acid beams at lower temperature range (25°C to 45°C). According to the nature of heating, maximum deflection in the range of 0.503 cm to 1.082 cm corresponding to the temperature range of 63.443°C to 67.917°C is observed for polylactic acid beams. For natural fibre braided fabric/polylactic acid beams, the maximum deflection range is 0.826 cm to 0.105 cm corresponding to the temperature range of 57.031°C to 44.742°C according to the heating condition. Thermal deflection of natural fibre braided fabric beam is sensitive to testing orientation of the beam and maximum deflection for warp loading is 29% to 54% lower than the weft loading.

Experimental Study on Transformation Plasticity in Terms of Three-Point Bending System

2014 ◽  
Vol 626 ◽  
pp. 408-413 ◽  
Author(s):  
M. Arif Hamdam ◽  
Shigeru Nagaki ◽  
Kenichi Oshita
Keyword(s):  
Phase Transformation ◽  
Martensite Phase ◽  
The Other ◽  
Maximum Deflection ◽  
Transformation Plasticity ◽  
Three Point Bending ◽  
Bending Stresses ◽  
Simple Support ◽  
Plasticity Coefficient ◽  
Forced Cooling

Three-point bending system with one end simple support and the other end fix support has been proposed to analyze the transformation plasticity (TP) behavior and obtain transformation plasticity coefficient. In this investigation two types of materials SCM440 steel and S45C steel have been studied. The specimens were heated to austenite temperature and the temperature kept constant for several minutes, then cooling and loading processes were performed. Austenite to martensite phase transformation with forced cooling for SCM440 steel and austenite to pearlite phase transformation with natural cooling for S45C steel due to bending stresses have been occurred. The deflections of specimen were measured during loading process. By obtaining the maximum deflection due to transformation plasticity, the transformation plasticity coefficient was determined.

Cooling and Cracking of Technical HLW Glass Products: Experimental and Numerical Studies

1988 ◽  
Vol 127 ◽  
Author(s):  
Bernhard Kienzler
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Thermal Power ◽  
Radioactive Decay ◽  
Measured Temperature ◽  
Flow Conditions ◽  
Cooling Process ◽  
Model Calculations ◽  
Numerical Studies ◽  
Temperature Distributions

ABSTRACTVarious cooling procedures have been applied to canisters filled with inactive simulated HLW glass and the measured temperature distributions have been compared with numerically computed data. Stress computations of the cooling process were carried out with a finite element method. Only those volume elements having temperatures below the transformation temperature Tg were assumed to contribute thermoelastically to the developing stresses. Model calculations were extended to include real HLW glass canisters with inherent thermal power. The development of stress as a function of variations of heat flow conditions and of the radioactive decay was studied.

Investigation and Application of Forced Cooling of WH 600MW Steam Turbine

2013 ◽  
Vol 732-733 ◽  
pp. 242-249
Author(s):  
Yong Feng Shi ◽  
Jian Qun Xu ◽  
Lin Ma
Keyword(s):  
Numerical Analysis ◽  
Steam Turbine ◽  
Cooling Rate ◽  
Control Strategy ◽  
Cooling Condition ◽  
Practical Application ◽  
Cooling Process ◽  
Quantitative Calculation ◽  
Forced Cooling ◽  
Cooling Air

With a long natural cooling time after a shutdown of steam turbine restricting its available coefficient, this paper presented the analysis and application of a forced cooling process to sub-critical steam turbine. The radiating mechanism of natural cooling was analyzed theoretically, and the required amount of cooling air was calculated for a WH 600MW steam turbine. Moreover, the cooling rate with no life loss principle was determined by the method of quantitative calculation and numerical analysis, together with safety analysis. The research discussed the control strategy of practical application according with steam turbine characteristic and applied to operation, which provided theoretical guidance for the optimization of cooling condition.

Inelastic Electron-Matter Interactions

1978 ◽  
Vol 36 (3) ◽  
pp. 259-267
Author(s):  
J. Silcox
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Chemical Structure ◽  
Inelastic Electron ◽  
Primary Concern ◽  
Unique Probe ◽  
Introductory Paper ◽  
Elastic Processes ◽  
Experimental Level ◽  
Inelastic Processes

In this introductory paper, my primary concern will be in identifying and outlining the various types of inelastic processes resulting from the interaction of electrons with matter. Elastic processes are understood reasonably well at the present experimental level and can be regarded as giving information on spatial arrangements. We need not consider them here. Inelastic processes do contain information of considerable value which reflect the electronic and chemical structure of the sample. In combination with the spatial resolution of the electron microscope, a unique probe of materials is finally emerging (Hillier 1943, Watanabe 1955, Castaing and Henri 1962, Crewe 1966, Wittry, Ferrier and Cosslett 1969, Isaacson and Johnson 1975, Egerton, Rossouw and Whelan 1976, Kokubo and Iwatsuki 1976, Colliex, Cosslett, Leapman and Trebbia 1977). We first review some scattering terminology by way of background and to identify some of the more interesting and significant features of energy loss electrons and then go on to discuss examples of studies of the type of phenomena encountered. Finally we will comment on some of the experimental factors encountered.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

Characterization of lead-bearing phases in municipal waste combustor fly ash

1996 ◽  
Vol 54 ◽  
pp. 516-517
Author(s):  
L. L. Sutter ◽  
G. R. Dewey ◽  
J. F. Sandell
Keyword(s):  
Fly Ash ◽  
Bottom Ash ◽  
Municipal Waste ◽  
Primary Concern ◽  
Leaching Behavior ◽  
Waste Combustion ◽  
Lead And Cadmium ◽  
Lead Speciation ◽  
Accepted Practice

Municipal waste combustion typically involves both energy recovery as well as volume reduction of municipal solid waste prior to landfilling. However, due to environmental concerns, municipal waste combustion (MWC) has not been a widely accepted practice. A primary concern is the leaching behavior of MWC ash when it is stored in a landfill. The ash consists of a finely divided fly ash fraction (10% by volume) and a coarser bottom ash (90% by volume). Typically, MWC fly ash fails tests used to evaluate leaching behavior due to high amounts of soluble lead and cadmium species. The focus of this study was to identify specific lead bearing phases in MWC fly ash. Detailed information regarding lead speciation is necessary to completely understand the leaching behavior of MWC ash.

Governing Diversity: Reflections on the Doctrine and Tradition of Religious Accommodation in Islam

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Dr. Muhammad Mushtaq ◽  
Muhammad Riaz Mahmood
Keyword(s):  
Power Sharing ◽  
Primary Concern ◽  
Peaceful Coexistence ◽  
Religious Traditions ◽  
Faith Based ◽  
Religious Accommodation ◽  
Pluralistic Approach ◽  
Inclusive Governance ◽  
Multicultural Policies ◽  
Islamic Values

The problématique of governing diversity has attracted a great deal of scholarly attention but literature has largely overlooked the challenges appertaining to growing religious diversity in many places. The contemporary power sharing models and multicultural policies which are of a secular nature fall short of the expectations to foster peaceful coexistence in multi-religious societies. The primary concern of this paper is to manifest how religion can help us to lessen faith based violence. It is argued that religious traditions may offer valuable insights to design more inclusive governance. In this backdrop, the current paper evaluates the Islamic values of religious accommodation to gauge how helpful they are for designing inclusive policies in religiously diverse societies. The analysis illustrates that Islamic doctrine contemplates the politics of accommodation and forbearance. The pluralistic approach of Islam offered religious autonomy to non-Muslims in the state of Madinah. The ‘millet system’ established by the Ottoman Empire is widely admired for granting non-territorial autonomy in the matters related to religion, culture, and personal laws to non-Muslims. This display of an Islamic pluralistic approach at different junctures of Muslim history attests the capacity of the Islamic values of accommodation to nurture peaceful coexistence in modern societies. However, it requires a more unbiased and rigorous analysis to convince the global audience in this regard.

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