Numerical analysis of factors influencing thermal effects generated by cavitation flow of cryogenic fluids

2020 ◽  
Vol 34 (17) ◽  
pp. 2050184 ◽  
Author(s):  
Suguo Shi ◽  
Guoyu Wang
Keyword(s):  
Thermal Effect ◽  
Liquid Nitrogen ◽  
Thermal Effects ◽  
Dynamic Pressure ◽  
Density Ratio ◽  
Cavitation Flow ◽  
Cryogenic Fluids ◽  
Factors Influencing ◽  
Fluid Properties ◽  
Cryogenic Liquids

Thermal effects dramatically impact on the cavitation dynamics of cryogenic fluids. Thus, to study the thermal effect factors influencing cryogenic cavitation, numerical simulations were conducted considering an axisymmetric ogive and a 2D quarter caliber hydrofoil in liquid nitrogen and hydrogen, respectively. The modified Merkle cavitation model and filter-based turbulence model were applied to account for the thermodynamic properties of the fluid. The energy equation was modified considering the cavitation phase change effects. Compared to the experimental data, the numerical method satisfactorily predicts the cryogenic cavitation flows. Based on the numerical results, the thermal effect characteristics in the cavitation flow of cryogenic fluids were investigated. The thermal effects in cryogenic cavitation is obvious when vapor content in constant location is considerably low, where the cavity becomes more porous and the interface becomes less distinct. The factors influencing the thermal effects in cavitation such as the temperature, fluid type and velocity were analyzed. Findings showed that thermal effects of cavitation were prominent around the critical temperature of cryogenic liquids. Compared to the thermal effects in liquid nitrogen, those in liquid hydrogen were more distinct because of the changes in the density ratio, vapor pressure and other fluid properties. When the flow velocity is higher, the thermal effects of cavitation are suppressed as the pressure depression caused by evaporation is much smaller than the dynamic pressure.

Thermodynamic Parameter on Cavitation in Space Inducer

2012 ◽  
Author(s):  
Yoshiki Yoshida ◽  
Kengo Kikuta ◽  
Kazuki Niiyama ◽  
Satoshi Watanabe
Keyword(s):  
Thermal Effect ◽  
Liquid Nitrogen ◽  
Thermodynamic Parameter ◽  
Latent Heat ◽  
Transit Time ◽  
Scaling Law ◽  
Operating Conditions ◽  
Thermal Time ◽  
Optical Visualization ◽  
Cryogenic Liquids

Cavitation is physically “a vaporization of liquid” which needs latent heat for phase change. A cavity grows in the liquid, so the latent heat of vaporization can only be supplied by the liquid surrounding the cavity. Thus, the liquid close to the interface region of the cavity is cooled down. In general, cryogenic liquids are very thermosensitive. For liquid hydrogen and oxygen used in rocket propulsion, the temperature in the cavity, i.e., the vapor pressure in the cavity, is lower than those of the liquid bulk. Thanks to this thermal effect, cavitation in cryogenic liquids is less developed than that in water at room temperature. This thermal effect on cavitation is beneficial in that it improves cavitation performance and alleviates cavitation instability in space inducers. In previous works, we investigated the relationship between the thermodynamic effect and the cavitation instabilities, e.g., rotating cavitation and cavitation surge, with a focus on the cavity length as an indication of cavitation. In the present work, first, aspects of cavitation in the inducer were observed by direct optical visualization in liquid nitrogen. Second, joint experiments in liquid nitrogen and cold water were conducted on a cavitaing inducer. In nitrogen experiments, operating conditions, i.e., rotational speed and liquid temperature, were varied to determine the cavitation scaling law. Through these experimental results, characteristic times, namely, the transit time for bubble growth and the characteristic thermal time introduced from the thermal property, were investigated as a cavitation thermodynamic parameter. It was found out that the adjustment of cavitation number has a good correlation with the ratio of the transit time and the characteristic thermal time.

Cavitation flow instability of subcooled liquid nitrogen in converging–diverging nozzles

Cryogenics ◽  
2012 ◽  
Vol 52 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Katsuhide Ohira ◽  
Tadashi Nakayama ◽  
Takayoshi Nagai
Keyword(s):  
Liquid Nitrogen ◽  
Flow Instability ◽  
Cavitation Flow ◽  
Subcooled Liquid

Development of an Electrohydrodynamic Injection Micropump for Cryogenic Cooling

2003 ◽  
Author(s):  
J. Darabi ◽  
H. Wang
Keyword(s):  
Experimental Investigation ◽  
Liquid Nitrogen ◽  
Pressure Head ◽  
Cryogenic Cooling ◽  
Maximum Pressure ◽  
Base Length ◽  
Inhomogeneous Electric Field ◽  
Cooling Systems ◽  
Pumping System ◽  
Cryogenic Liquids

Cryogenic cooling has become a widely adopted technique to improve the performance of electronics and sensors. A potential application of an electrohydrodynamic (EHD) pumping system is its use in pumping fluids in cryogenic cooling systems. In this paper we present the results of a theoretical/experimental investigation to study the feasibility of using an EHD injection micropump for pumping liquid nitrogen. First, the mechanisms of charge transport and ionization phenomenon in cryogenic liquids are discussed. Next, the design and fabrication of an EHD injection micropump that employs an array of interdigitated saw-tooth/plane electrodes are described. Finally, experimental results and observations are presented. An asymmetric saw-tooth/plane geometry was designed to achieve strong inhomogeneous electric field. Each saw-tooth had a base length of 10 μm with a tip angle of 60°. The gap between emitter and collector electrodes was 20 μm and the distance between each stage (a pair of emitter and collector electrodes) from neighboring stage was 40 μm. The dimensions of the patterned area were 10 mm by 20 mm allowing approximately 300 stages to be fabricated along the length of the micropump. The maximum pressure head achieved by this micropump was 550 Pa and 205 Pa for HFE-7100 and liquid nitrogen, respectively.

scholarly journals The Oil-Bearing Strata of Permian Deposits of the Ashal’cha Oil Field Depending on the Content, Composition, and Thermal Effects of Organic Matter Oxidation in the Rocks

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Galina P. Kayukova ◽  
Anastasiya N. Mikhailova ◽  
Igor P. Kosachev ◽  
Dmitry A. Emelyanov ◽  
Mikhail A. Varfolomeev ◽  
...  
Keyword(s):  
Organic Matter ◽  
Thermal Effect ◽  
Mineral Composition ◽  
Oil Recovery ◽  
Thermal Effects ◽  
Total Content ◽  
Hydrocarbon Composition ◽  
Oil Field ◽  
Scanning Calorimetry ◽  
Organic Matter Oxidation

The features of the oil-bearing capacity of the productive strata of Permian deposits in the interval of 117.5-188.6 m along the section of individual wells of the Ashal’cha field of heavy superviscous oil (Tatarstan) were revealed depending on the content, composition, and thermal effects of organic matter (OM) oxidation in the rocks. It is shown that the rocks are very heterogeneous in their mineral composition and in the content of both free hydrocarbons by extraction with organic solvents and insoluble OM closely associated with the rock. The total content of OM in rocks varies from 1.72 to 9.12%. The features of group and hydrocarbon composition of extracts from rocks are revealed depending on their mineral composition and the content of organic matter in them. According to the molecular mass distribution of alkanes of normal and isoprenoid structure, extracts from rocks are differentiated according to three chemical types of oil: type A1, in which n-alkanes of composition C14 and above are present, and types A2 and B2, in which n-alkanes are destroyed to varying degrees by processes microbial destruction, which indicates a different intensity of biochemical processes in productive strata of Permian sediments. These processes lead to a decrease in the amount of OM in the rocks and an increase in the content of resins and asphaltenes in the oil extracted from them, as well as an increase in the viscosity of the oil. Using the method of differential scanning calorimetry of high pressure, it was found that the studied rock samples differ from each other in quantitative characteristics of exothermic effects in both low-temperature (LTO) 200-350°С and high-temperature (HTO) 350-600°С zones of OM oxidation. The total thermal effect of destruction processes of OM depends on the content of OM in the rocks and its composition. The research results show that when heavy oil is extracted using thermal technologies, the Permian productive strata with both low and high OM contents will be involved in the development, and the general thermal effect of the oxidation of which will contribute to increased oil recovery.

Comparative investigation of the optical spectroscopic and thermal effect in Nd3+-doped nanoparticles

Nanoscale ◽  
2019 ◽  
Vol 11 (21) ◽  
pp. 10220-10228 ◽  
Author(s):  
Shuai Wang ◽  
Bin Shen ◽  
Han-Lin Wei ◽  
Zixiao Liu ◽  
Zhigang Chen ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Thermal Effect ◽  
Upconversion Luminescence ◽  
Comparative Investigation ◽  
Transfer Mechanism ◽  
Energy Transfer Mechanism ◽  
Factors Influencing

The factors influencing upconversion luminescence, the energy transfer mechanism and their thermal effect in Nd3+-doped nanoparticles were comprehensively investigated.

Rewet Temperature Correlations for Liquid Nitrogen Boiling Pipe Flows Across Varying Flow Conditions and Orientations

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
S. R. Darr ◽  
J. Dong ◽  
N. Glikin ◽  
J. W. Hartwig ◽  
J. N. Chung
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Liquid Nitrogen ◽  
Heat Transfer Process ◽  
Transport Processes ◽  
Liquid Oxygen ◽  
Cryogenic Fluids ◽  
Wide Range ◽  
Leidenfrost Temperature ◽  
Phase Change Heat Transfer

In many convective liquid–vapor phase-change heat transfer engineering applications, cryogenic fluids are widely used in industrial processes, spacecraft and cryosurgery systems, and so on. For example, cryogens are usually used as liquid fuels such as liquid hydrogen, liquid methane, and liquid oxygen in the rocket industry, liquid nitrogen and helium are frequently used to cool superconducting magnetic device for medical applications. In these systems, proper transport, handling, and storage of cryogenic fluids are of extreme importance. Among all the cryogenic transport processes performed in room temperatures, quenching, also termed chilldown, is an unavoidable initial, transient phase-change heat transfer process that brings the system down to the cryogenic condition. The Leidenfrost temperature or rewet temperature that signals the end of film boiling is practically considered the completion point of a quenching process. Therefore, rewet temperature has been considered the most important parameter for the engineering design of cryogenic thermal management systems. As most of the previous correlations for predicting the Leidenfrost temperature and the rewet temperature have been developed for water, they are shown to disagree with recent liquid nitrogen pipe chilldown experiments in upward and downward flow directions over a wide range of flow rates, pressures, and degrees of inlet subcooling. In addition to a complete review of the literature, two modified correlations are presented, one based on bubble growth and another based on the theoretical maximum limit of superheat. Each correlation performs well over the entire dataset.

The Thermal Effect in Wheel and Rail during the Brake of Port Crane

2012 ◽  
Vol 487 ◽  
pp. 879-883
Author(s):  
Jiang Wei Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Model ◽  
Thermal Effect ◽  
Thermal Effects ◽  
Element Model ◽  
The Finite Element Method ◽  
Finite Element Software ◽  
Frictional Coefficients ◽  
The Finite Element Model

With the port crane getting bigger and heavier, and also moving much faster than before, the thermal effect in wheel and rail during the brake process can be a reason of the failure of port crane. In this paper, the thermal effect during the brake process of port crane is studied using the finite element method. Based on the finite element model, the ANSYS10.0 finite element software is used. The thermal effects under different coefficients are discussed. Three different slide speed of wheel, two different loads of crane, and three different frictional coefficients are applied. The importance of the different coefficients is obtained from the numerical results.

scholarly journals Thulium and holmium ureterolithotripsy: evaluation of thermal effects on the ureter by measuring the temperature of the irrigation fluid in vitro

2021 ◽  
Vol 14 (2) ◽  
pp. 26-30
Author(s):  
S.V. Popov ◽  
◽  
I.N. Orlov ◽  
D.A. Sytnik ◽  
M.M. Suleimanov ◽  
...  
Keyword(s):  
Thermal Effect ◽  
Pulse Duration ◽  
Thermal Effects ◽  
Surgical Intervention ◽  
Daily Practice ◽  
Thulium Laser ◽  
Irrigation Fluid ◽  
Lower Temperature ◽  
Obstructive Pyelonephritis

Introduction. Urolithiasis refers to one of the most common diseases of the genitourinary system, which the urologist meets in his daily practice. When a stone is located in the ureter, surgical intervention is often required to restore the passage of urine and prevent the development of obstructive pyelonephritis. Currently, the holmium or thule laser ureterolithotripsy is condidered the «gold standard» of surgical treatment of ureteral calculi. The thermal effect on the ureteral wall when using a laser may be one of the reasons for the postoperative ureteral strictures development. The aim of our study is to compare in vitro thermal effects of these types of laser on the ureter wall by evaluating the change in the temperature of the irrigation fluid when they are used. Materials and methods. A tube with a diameter of 5 mm, which imitated the ureter, was placed in an aqueous medium with a temperature of 36°C. A temperature sensor (HI 98509 Checktemp 1) was installed in its lumen, at a 3 mm distance from the laser fiber. The time when the irrigation fluid reaches a temperature of 43°C, as well as its temperature at a pulse duration of 3 seconds at an irrigation rate of 25 and 50 ml/sec in the dusting and fragmentation modes, were recorded. Results and discussion. It was found that when using a thulium laser, regardless of the flow rate of the irrigation fluid, an increase in its temperature to 43°C is achieved for a longer time. Also, a lower temperature of the irrigation fluid with a pulse duration of 3 second is recorded using thulium laser. The obtained data allow us to assume that the use of a thulium laser is accompanied by a lower thermal effect on the ureter wall. Conclusion. In this study, we found that when using a thulium laser (Fiberlase U2) in the fragmentation and sputtering modes, a slower increase in the temperature of the irrigation liquid is observed than when using a holmium laser (Lumenis VersaPulse 100W), regardless of the irrigation speed. At a 3 second pulse , a lower temperature of the irrigation fluid was recorded during the use of the thulium laser.

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