Thermophysical properties measurement of molten silicon by high-temperature electrostatic levitator: density, volume expansion, specific heat capacity, emissivity, surface tension and viscosity

2000 ◽  
Vol 208 (1-4) ◽  
pp. 313-321 ◽  
Author(s):  
Won-Kyu Rhim ◽  
Kenichi Ohsaka
2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Zhengbin Wu ◽  
Shu Jiang ◽  
Lei Wang ◽  
Yiguo Zhang

Abstract Air-assisted steam injection is a new technique for heavy oil reservoir exploitation. This paper focused on the thermophysical properties of the air/steam system, such as density, viscosity, specific heat capacity, enthalpy, and thermal conductivity coefficient, and these have been calculated using the Redlich–Kwong equation of state (RK EOS). The viscosity of the air/steam system under high temperature and high pressure was calculated with the corresponding state principle and rectified with the Dean–Stiel residual viscosity method. The results showed that compared with the saturated steam of the same mass, the viscosity, specific heat capacity, thermal conductivity, and enthalpy of the air/steam mixture decreased, while the specific volume increased, which indicated that the addition of air to steam weakened the thermal effect of the steam and makes use of the heat insulation and thermal expansion of air. This study can provide guidance for parameter design of air-assisted steam injection for heavy oil recovery.


2019 ◽  
Vol 15 ◽  
Author(s):  
Andaç Batur Çolak ◽  
Oğuzhan Yıldız ◽  
Mustafa Bayrak ◽  
Ali Celen ◽  
Ahmet Selim Dalkılıç ◽  
...  

Background: Researchers working in the field of nanofluid have done many studies on the thermophysical properties of nanofluids. Among these studies, the number of studies on specific heat are rather limited. In the study of the heat transfer performance of nanofluids, it is necessary to increase the number of specific heat studies, whose subject is one of the important thermophysical properties. Objective: The authors aimed to measure the specific heat values of Al2O3/water, Cu/water nanofluids and Al2O3-Cu/water hybrid nanofluids using the DTA method, and compare the results with those frequently used in the literature. In addition, this study focuses on the effect of temperature and volume concentration on specific heat. Method: The two-step method was used in the preparation of nanofluids. The pure water selected as the base fluid was mixed with the Al2O3 and Cu nanoparticles and Arabic Gum as the surfactant, firstly mixed in the magnetic stirrer for half an hour. It was then homogenized for 6 hours in the ultrasonic homogenizer. Results: After the experiments, the specific heat of nanofluids and hybrid nanofluid were compared and the temperature and volume concentration of specific heat were investigated. Then, the experimental results obtained for all three fluids were compared with the two frequently used correlations in the literature. Conclusion: Specific heat capacity increased with increasing temperature, and decreased with increasing volume concentration for three tested nanofluids. Cu/water has the lowest specific heat capacity among all tested fluids. Experimental specific heat capacity measurement results are compared by using the models developed by Pak and Cho and Xuan and Roetzel. According to experimental results, these correlations can predict experimental results within the range of ±1%.


2004 ◽  
Vol 19 (2) ◽  
pp. 590-594 ◽  
Author(s):  
P-F. Paradis ◽  
T. Ishikawa ◽  
S. Yoda

Several thermophysical properties of liquid and supercooled ruthenium were measured using electrostatic levitation. Over the 2225–2775 K temperature interval, the density can be expressed as ρ(T) = 10.75 × 103 – 0.56(T – Tm)(kg ⋅ m−3) with Tm = 2607 K. In addition, the surface tension can be expressed as σ(T) = 2.26 × 103 – 0.24(T – Tm)(mN ⋅ m−1) and the viscosity as η(T) = 0.60 exp[4.98 × 104/(RT)] (mPa ⋅ s) over the 2450–2725 K range. The isobaric heat capacity was estimated as CP(T) = 35.9 + 1.1 × 10−3(T – Tm)[(J/(mol K)] over the 2200–2750 K span by assuming a constant emissivity. The volume expansion coefficient, the enthalpy, and the entropy of fusion were also calculated as 5.2 × 10−5 K−1, 29.2 kJ ⋅ mol−1, and 11.2 J/(mol K).


2009 ◽  
Vol 48 (5) ◽  
pp. 05EC02 ◽  
Author(s):  
Masashi Kuwahara ◽  
Osamu Suzuki ◽  
Kouichi Tsutsumi ◽  
Takashi Yagi ◽  
Naoyuki Taketoshi ◽  
...  

1999 ◽  
Vol 14 (9) ◽  
pp. 3713-3719 ◽  
Author(s):  
Paul-François Paradis ◽  
Won-Kyu Rhim

Six thermophysical properties of both solid and liquid zirconium measured using the high-temperature electrostatic levitator at the Jet Propulsion Laboratory are presented. These properties are density, thermal expansion coefficient, constant pressure heat capacity, hemispherical total emissivity, surface tension, and viscosity. For the first time, we report the densities and the thermal expansion coefficients of both the solid as well as liquid Zr over wide ranges of temperatures. Over the 1700–2300 K temperature span, the liquid density can be expressed as ρ1(T) = 6.24 × 103 – 0.29(T – Tm) kg/m3 with Tm = 2128 K, and the corresponding volume expansion coefficient as α1 = 4.6 × 10−5/K. Similarly, over the 1250–2100 K range, the measured density of the solid can be expressed as ρs(T) = 6.34 × 103 – 0.15(T – Tm), giving a volume expansion coefficient αs = 2.35 × 10−5/K. The constant pressure heat capacity of the liquid phase could be estimated as Cpl(T) = 39.72 – 7.42 × 10−3(T – Tm) J/(mol/K) if the hemispherical total emissivity of the liquid phase εT1 remains constant at 0.3 over the 1825–2200 K range. Over the 1400–2100 K temperature span, the hemispherical total emissivity of the solid phase could be rendered as εTs(T) = 0.29 – 9.91 × 103 (T – Tm). The measured surface tension and the viscosity of the molten zirconium over the 1850–2200 K range can be expressed as ς(T) = 1.459 × 103 – 0.244 (T – Tm) mN/m and as η(T) = 4.83 – 5.31 × 10−3(T – Tm) mPa s, respectively.


2012 ◽  
Vol 184-185 ◽  
pp. 1226-1231
Author(s):  
Meng Ying Liu ◽  
Tao Zhou ◽  
Wen Zhong Zou ◽  
Zi Wei Su

The article chooses Na, LiPb and LBE three kinds of metal coolant, and makes a comparative analysis of the thermophysical properties of Na, LiPb and LBE when they are at liquid state. The results show that Na has the lowest density and the largest thermal conductivity and specific heat capacity. There is a small difference between LBE and LiPb in terms of density, thermal conductivity and specific heat capacity. LiPb has the largest kinematic viscosity. The thermal conductivity of Na decreases as temperature rises, which is opposite of LBE and LiPb. The kinematic viscosity of LiPb increases as temperature rises. Considering thermal conductivity and specific heat capacity, LBE and LiPb are not the best coolant. However, their high densities can economize equipments and materials at the same time. When it flows, LiPb’s heat transfer capacity gets larger as temperature rises, this character can not be ignored in fusion reactor.


2016 ◽  
Vol 638 ◽  
pp. 113-119 ◽  
Author(s):  
X.K. Gao ◽  
X. Wen ◽  
H. Zhou ◽  
Q. Zhu ◽  
J.L. Wang ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2287
Author(s):  
Lubos Kristak ◽  
Ivan Ruziak ◽  
Eugenia Mariana Tudor ◽  
Marius Cătălin Barbu ◽  
Günther Kain ◽  
...  

The effects of using 100% larch bark (Larix decidua Mill) as a raw material for composite boards on the thermophysical properties of this innovative material were investigated in this study. Panels made of larch bark with 4–11 mm and 10–30 mm particle size, with ground bark oriented parallel and perpendicular to the panel’s plane at densities varying from 350 to 700 kg/m3 and bonded with urea-formaldehyde adhesive were analyzed for thermal conductivity, thermal resistivity and specific heat capacity. It was determined that there was a highly significant influence of bulk density on the thermal conductivity of all the panels. With an increase in the particle size, both parallel and perpendicular to the panel´s plane direction, the thermal conductivity also increased. The decrease of thermal diffusivity was a consequence of the increasing particle size, mostly in the parallel orientation of the bark particles due to the different pore structures. The specific heat capacity is not statistically significantly dependent on the density, particle size, glue amount and particle orientation.


Sign in / Sign up

Export Citation Format

Share Document