3 edition of Analytical study of the liquid phase transient behavior of a high temperature heat pipe found in the catalog.
Analytical study of the liquid phase transient behavior of a high temperature heat pipe
1988 by University of California, Los Angeles, National Aeronautics and Space Administration, National Technical Information Service, distributor in [Los Angeles, Calif.], [Washington, DC, Springfield, Va .
Written in English
|Statement||by Gregory Lawrence Roche.|
|Series||NASA contractor report -- NASA CR-187426.|
|Contributions||United States. National Aeronautics and Space Administration.|
|The Physical Object|
phase change heat transfer (e.g., boiling and condensation). Further advances in phase change heat transfer will continue to take place motivated by new technologies such as micro-electronics, thermal management in space, advanced terrestrial and space power systems and processing of designed materials. An example of a new source of heat "turning on" within an object, causing transient conduction, is an engine starting in an automobile. In this case, the transient thermal conduction phase for the entire machine is over, and the steady state phase appears, as soon as the engine reaches steady-state operating temperature. In this state of steady. Abstract. The project’s main purpose was to design, build and test a compact heat exchanger for supercritical carbon dioxide (sCO 2) power cycle compact recuperator is required to operate at high temperature and high pressure differentials, bar (~2, psi), between streams of sCO onal project tasks included building a hot air-to-sCO 2 Heater heat .
The transient operation of the liquid phase of a high temperature heat pipe is studied. The study was conducted in support of advanced heat pipe applications that require reliable transport of high temperature drops and significant distances under a broad spectrum of operating : Gregory Lawrence Roche.
The purpose of the study is to develop an analytical model of the transient dynamics of the liquid phase in a high-temperature heat pipe.
The full system of governing equations, including boundary conditions, required to solve the liquid-phase heat-pipe problem are : Gregory L. Roche, Farrokh Issacci, Ivan Catton.
Analytical study of the liquid phase transient behavior of a high temperature heat pipe [microform]: a thesis submitted in partial satisfaction of the requirements for the degree Master of Science in Mechanical Engineering / by Gregory Lawrence Roche University of California, Los Angeles ; National Aeronautics and Space Administration ; National Technical Information Service.
Analytical study of the liquid phase transient behavior of a high temperature heat pipe: a thesis submitted in partial satisfaction of the requirements for the degree Master of Science in Mechanical Engineering. EXPERIMENTAL AND ANALYTICAL STUDY OF THE TRANSIENT SOLIDIFICATION OF A WARM LIQUID FLOWING OVER A CHILLED FLAT PLATE by Joseph M.
Savino and Robert Siege1 Lewis Research Center SUMMARY Analytical predictions and experimental data are provided for the transient growth of a frozen layer that forms when a warm liquid flows over.
High-temperature Phase Change Material (PCM) is used as a thermal storage medium of a heat-pipe receiver in an advanced solar dynamic system. With both void cavity and natural convection considered, thermal performance of the heat-pipe receiver is numerically analyzed under gravity.
The results indicate that the PCM contained in the integrated heat pipe performs an averaging function of heat Cited by: 6.
A two-dimensional, heat pipe transient analysis model, ‘HPTAM’, is developed for simulating operations of fully-thawed heat pipes. The model is benchmarked using transient experimental data of a horizontal water heat by: A Numerical Analysis of High-Temperature Heat Pipe Startup From the Frozen State Y.
Cao, A Study of High-Temperature Heat Pipes With Multiple Heat Sources and Sinks: Part II—Analysis of Continuum Transient and Steady-State Experimental Data Cited by: Abstract A heat pipe is a self-contained structure which achieves very high thermal conductance by means of two-phase fluid flow with capillary circulation.
A quantitative engineering theory for the design and performance analysis of heat pipes is given. iynC QUALITY INSPECTED Sptoiad3 Aoe*8sloQ For HTIS GRAAI DTIC TAB Unannounced Cited by: ANALYTICAL HEAT TRANSFER Mihir Sen Department of Aerospace and Mechanical Engineering University of Notre Dame Notre Dame, IN May 3, A transient model of the vapor core of high temperature heat pipes has been developed.
Model trends show good agreement with both analytical steady state calculations and experimentally observed startup behavior. Diffusion does not have a large effect on heat pipe performance for this particular by: 2. Sobhan et al.  presented a computational analysis to study the transient analysis of a flat heat pipe, where an energy balance was applied to compute the mass flux at the liquid vapor interface.
Type curves are generated to analyze the pressure-transient behavior. The second radial-flow (SRF) occurs for the MSHWs, and the duration of SRF depends on interference between segments.
The pressure-derivative curve during SRF equals to /N p (N p denotes the number of mainly producing segments (PS)) under weak interference between by: The capabilities of HPTAM, a two‐dimensional Heat Pipe Transient Analysis Model, are extended to include modeling of free‐molecular and transition vapor flow regimes.
varying ambient air temperatures. A one-dimensional transient heat conduction mathematical model was developed to estimate the freezing time of the liquid in the pipe. The model was based on the separation of variables method for a finite length-scale solidification problem, and was verified with the experimental transient temperature data.
Although no study was conducted to investigate the application of nanofluid in a heat pipe with multiple heat sources, some research groups , ,  studied the performance of cylindrical heat pipe with discrete heat sources using water as working by: 7.
These transient conditions resulting in high pressures can cause pipe failures by damaging valves and fittings. In this study, basic equations for solving transient analysis problems are derived using method of characteristics.
Two example problems are presented. In this paper, we provide new analytical and semi-analytical solutions based on a coupled wellbore/reservoir thermal model to investigate the information content of transient temperature measurement made within the vertical wellbore across from the producing horizon or at a gauge depth above it during drawdown and buildup by: 4.
the heat pipe, capillary pumping forces, heating and cooling conditions. In the present study, the transient operations of different conventional room-temperature heat pipes were investigated analytically, including the capillary dryout and rewetting behaviors occurring at the evaporator section during startups.
TheAuthor: Pascal O. Brocheny. A material's specific heat: is required for transient Uncoupled heat transfer analysis, transient Fully coupled thermal-stress analysis, transient Coupled thermal-electrical analysis, and Adiabatic analysis; must appear in conjunction with a density definition (see Density); can be linear or nonlinear (by defining it as a function of temperature); and.
A brief overview of the heat pipe history is given and the different applications are presented. A global review of the recent studies on heat pipes is then presented.
Advances are identified in terms of heat pipe characterisation, scientific issues linked to the working fluid, understanding of phase-change heat transfer in thin liquid films Cited by: 9. Hydraulic analysis of unsteady flow in pipe networks. London: Macmillan.
Hydraulic analysis of unsteady flow in pipe networks / J. Fox Macmillan London. Wikipedia Citation. Please see Wikipedia's template documentation for further Analytical study of the liquid phase transient behavior of a high temperature heat pipe [microform]: a.
Heat pipes are liquid-vapor phase change devices that can transfer heat from a hot source to a cold source through capillary forces generated by the flow of liquid in a wick or other porous media.
To accomplish this, heat pipes take advantage of the latent heat of an internal working fluid to transfer heat. Due to the complexity of getting as analytical solution for heat pipe operation, some models without the effects of shearing stress on the liquid-vapor interface has been intensively study by .
The first analytical model for micro-heat pipe was presented by Cotter . The capillary pressure gradient due to the. store large amounts of heat at a close-to-constant temperature during the phase change (solid to liquid and vice versa). This latent heat capacity can be used to provide higher performance while reducing hot spots.
Detailed modeling of the phase change behavior is essential for the design and evaluation of systems with Size: 3MB. The temperature distribution along the heat pipe, input heat to evaporator section, and output heat from condenser were monitored.
A comprehensive mathematical model was developed to investigate the steady-state heat transfer performance of a two-phase closed heat pipe. A steady state analytical model. Abstract This paper presents new semilog-straight line and temperature-derivative methods (similar to pressure-derivative method commonly used in pressure transient analysis) for interpreting and analyzing temperature transient data from constant-rate drawdown and buildup tests conducted in infinite-acting reservoirs containing slightly compressible fluid of constant.
International Heat Pipe Conference inregarding operating conditions, Dr. Polasek stated that the“For successful operation of an oscillating heat pipe, liquid plugs and vapor bubbles must coexist inside the capillary tube along its length. This can be achieved by vacuuming the tube and then partially filling it with a working fluid.
solved by laboratory analysis. It requires observation of test specimens in actual operating environments in pilot plants or full-size units. A discussion of the corrosion behavior of stainless steels in various high-temperature environments begins on page Cost The consideration of cost in selecting materials for high-temperature serviceFile Size: KB.
Three dimensional numerical investigation is carried out to study the influence of geometry on thermal. behavior of flat heat pipe. Two phase mixture model has been formulated to investigate the phase change.
phenomena during steady state operation of flat heat by: 3. This study Above all, various techniques such as forced air cooling, liquid circulation cooling, phase change material cooling, and heat pipe cooling have been applied to Battery thermal management system (BTMS).
However, these methods face the challenge of complicated structures as well as large investments. Liquid–vapor phase behavior and operating characteristics of the capillary evaporator of a loop heat pipe at start-up International Journal of Thermal Sciences, Vol.
Experimental and theoretical study of a novel loop heat pipeCited by: The heat pipe is a capillary-driven and two-phase flow device, capable of transporting and converting large amounts of energy with minimal losses. As a means of thermal management, uses of heat pipe technology not only include thermal control of satellites and spacecrafts in aerospace applications, but also the cooling of electronic components for ground : Pascal O.
Brocheny. An experimental study on ﬂow patterns and heat transfer characteristics during cryogenic chilldown in a vertical pipe Hong Hua,⇑, Jacob N. Chunga, Samuel H. Amberb a Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, FloridaUnited States bDepartment of Physics and Nuclear Engineering, U.S.
Military Academy, West point, File Size: 1MB. Heat pipe. A heat pipe is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces.
At the hot interface of a heat pipe a liquid in contact with a thermally conductive solid surface turns into a vapor by absorbing heat from that surface.
The heat pipe has many advantages compared with other cooling devices such as the following: The effective thermal conductivity is very high since the heat pipe operates on a closed two-phase cycle. Therefore, it can transport large quantity of heat with very small temperature difference between evaporator and condenser : Mohamed H.A.
Elnaggar, Ezzaldeen Edwan. Titanium-Halide Heat Pipes. The two titanium halide heat pipes examined had very different responses. Heat Pipe 4, which had CP Ti with a TiBr 4 working fluid, had minimal corrosion. Like Heat Pipes andthere was evidence of some change at the surface as the BSE images showed the outer 10 micrometers had notably less mottling than the core.
The gas-phase reaction models presume that exothermic gas-phase reactions and their heat feedback to the propellant surface are the primary mechanism of ignition. In spite of their contributions in correlating experimental data and providing qualitative understanding of ignition behavior, the solid-phase (or reactive solid), heterogeneous.
KEY WORDS: flow-induced vibration, pipeline, vibration analysis, vibration measurement, damper, NETPULS, dPIPE INTRODUCTION Vibration of High Energy pipelines very often is the cause of pipe and fitting cracking and other relevant problems.
Vibration is usually divided into two character types: steady-state and dynamic transient Size: KB. transient behaviors of large-scale bubbles with condensation. The objective of the present study is to verify the code for numerical simulations of relatively short-time-scale multi-phase, multi-component hydraulic problems, among which vaporization and condensation, or simultaneous heat and mass transfer, play an important role.
through the solidifying shell, during a sudden fluctuation in liquid level at the meniscus. The results show that thermal stress causes the exposed portion of the thin shell to bend towards the liquid, when there is a severe, sudden drop in liquid level.
In addition, the axial temperature gradient creates high transverse Size: KB.In spite of wide application of heat pipe in microelectronics cooling system, a complete understanding of heat pipe mechanism has not yet been completed. An experimental investigation of heat transfer performance of a heat pipe for dry condition and with three different liquids as acetone, methanol, and water having four fill ratios, for each liquid has been conducted in the present by: 3.ME Finite Element Analysis in Thermofluids Dr.
Cüneyt Sert Chapter 1 Governing Equations of Fluid Flow and Heat Transfer Following fundamental laws can be used to derive governing differential equations that are solved in a Computational Fluid Dynamics (CFD) study  conservation of massFile Size: KB.