2 edition of Investigation of a variable conductance heat pipe found in the catalog.
An alkali‐metal Variable Conductance Heat Pipe (VCHP) was designed to allow multiple stops and restarts of the Stirling engine. A VCHP was designed for the Advanced Stirling Radioisotope Generator, with a °C heater head by: Approved for public release; distribution is unlimitedA variable conductance heat pipe with a length to diameter ratio of 96 to 1 was designed and constructed. The performance characteristics of both the conventional and gas loaded variable conductance modes of operation were : Wayne Ives Humphreys.
Heat pipe routines built into SINDA/FLUINT provide fast system-level solutions to modeling heat pipes when a full two-phase solution is not required. Both constant conductance (CCHP, also called FCHP), with or without noncondensible gas (NCG), and variable conductance (VCHP) pipes . Heat Pipe 1-Piece Vapor Chamber 2-Piece Vapor Chamber 20 Heat Pipes • Bend radius 3X diameter of heat pipe. Each 45 degree bend reduces Qmax by ~% • Flatten to 1/3 diameter of original pipe (typical) • Machining if pipe wall thickness permits. Allows direct contact with heat source 1-Piece Vapor Chamber • 10mm bend radius along File Size: 2MB.
Fig. 7–2. Transition from Constant Conductance to Variable Conductance Operation, Q =33 W, Test K05, Evap. No. 5, Ammonia - "Investigation of Two-Phase Behavior in Capillary Evaporators with Liquid Core Visualization". Thermal Performance of a Miniature Variable Conductance Loop Heat Pipe Loop Heat Pipes (LHP) of different designs are currently used in aerospace applications worldwide. Historically, LHPs were considered primarily as candidates for high power, high adverse elevation and high heat flux applications such as deployable radiators for Cited by: 5.
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VCHPs (variable conductance Heat Pipes) are used to control the temperature of equipment within narrow limits despite variations in heating load or cooling efficiency. A VCHP may also be used to avoid backwards conductance if the cooler happened to overheat, when it is Cited by: 1.
The heat pipe developed is titanium – ammonia –gas loaded variable heat pipe which has a heated reservoir (VCHP). Three grams as initial mass of pure nitrogen % was charged to the VCHP as non- condensable gas. This study has clarified that titanium is very desirable as heat pipe File Size: KB.
If you are just getting interested in heat pipes, Dunn and Reay is an excellent starting point. It covers all of the basics, which haven't changed since the book was written. It doesn't cover newer heat pipe variations, such as Pressure Controlled Heat Pipes and Variable Conductance Heat Pipes, or Loop Heat Pipes (LHPs).3/5(2).
Conductance Heat Pipe (CCHP), it is wise to start with the layout of a CCHP. There are three sections of a basic heat pipe with a working fluid enclosed inside the pipe. Various fluids are used in heat pipes and the selected fluid is based upon its saturation temperature and the temperature at which the heat pipe will be functioning.
LISTOFFIGURES pevaporflowdiagram 30 -gasflatfrontmodel 12 design 1° lheatpipedesign 17 5. Schematicdiagramofheatpipeandassociated. The variable conductance heat pipe (VCHP), sometimes called a specific variant the gas-controlled or gas-loaded heat pipe, has a unique feature that sets it apart from other types of heat pipe.
This is its ability to maintain a device mounted at the evaporator at a near constant temperature, independent of the amount of power being generated by the by: 1. Investigation of gravitational effects on a variable conductance heat pipe utilizing liquid crystal thermography - NASA/ADS Observations were made of the operation of a gas loaded, variable conductance heat pipe two inches in diameter and sixty inches by: 1.
A single-artery variable conductance arterial heat pipe was experimentally and numerically studied. To investigate the growth of the noncondensible.
gas supported bubbles, one-dimensional time-dependent conservation equations were solved by using the finite element method. In some applications, it is desirable to have the heat pipe transfer heat in only one direction; that is, when the source is warliier than the sink, the heat pipe would act in its normal high conductance mode, but when the sink temperature rises above the source, the heat pipe.
Variable Conductance Heat Pipe (VCHP) Variable Conductance Heat Pipes (VCHPs) are similar to standard heat pipes, with the addition of a Non-Condensable Gas (NCG). When heat is supplied to the evaporator, the working fluid vaporizes, and travels to the condenser, where it condenses.
Interchangeable Variable Conductance Heat Pipes for Sodium-Sulfur Batteries [John R. Hartenstine] on *FREE* shipping on qualifying offers. In this study, a novel Magnetically Variable Conductance Thermosyphon Heat Pipe (MVCTHP) was investigated experimentally. The possibility of deactivating a portion of evaporator length and.
Relationships are presented for the design of gas-controlled heat pipes with tanks of constant and variable volume. The theoretical and experimental result “A variable conductance heat pipe flight experiment,” AIAA Paper, No.
V.V. Investigation of gas-controlled heat pipes with tanks of constant and variable : V. Barsukov. feedback controlled variable heat pipe. Keywords: heat pipe, variable conductance heat pipe, heat transfer equations, transfer function of automatic systems) 1. INTRODUCTION The basic heat pipe is a closed container which has evacuated all non-condensable gases and contains a capillary structure (wick) and a small amount of a vaporizable fluid .
Description and orbit data of variable-conductance heat-pipe system for the communications technology satellite. Washington, D.C.: National Aeronautics and Space Administration, Scientific and Technical Information Branch ; [Springfield, Va.: For sale by the National Technical Information Service], (OCoLC) Material Type.
Investigation of the Performance of a Gas-Loaded Variable Conductance Heat Pipe by Keith Earl Reynolds Lieutenant Commander, United States Navy B.S., United States Naval Academy, Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN MECHANICAL ENGINEERING and MECHANICAL ENGINEER from the ma^at.
VARIABLE CONDUCTANCE HEAT PIPE TECHNOLOGY Final Research Report MARCH Prepared by W. ANDERSON 0. EDWARDS J. ENINGER B. MARCUS Contract No. NAS Prepared for AMES RESEARCH CENTER NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Moffett Fteld, Col ~forn~a i: i File Size: 3MB.
Comparison with conventional heat-pipe Figure 2 shows a structural comparison of a conventional heat-pipe and the variable-conductance heat-pipe (VCHP). In the conventional type, a small volume of work-ing fluid is sealed into an evacuated metal container.
The. Abstract Abstract — An experimental investigation is carried out to study the effects of nanofluid and mass of non-condensable gas on the thermal performance of variable conductance heat pipe by testing circular screen mesh wick heat pipe.
The nanofluid used is water-based CuO-nanofluid with the volume fraction of 1, 3 and 5 Vol.%. Power is only limited by the source and sink conditions Variable Conductance Heat Pipes and Pressure Controlled Heat Pipes can be used when a variable thermal link is required.
ACT’s heat pipe calculator can be used to estimate the performance of standard copper-water heat pipes. To date, a variety of devices has been introduced to achieve high turndown in spacecraft heat rejection systems such as mechanical louvers , variable conductance heat pipes [2, 3], two-loop.
Investigation of a gas regulatable heat pipe with a wicked reservoir. fabrication and testing of a variable conductance heat pipe for equipment control,” AIAA Paper, ().
3. “Investigation of heat and mass transfer in gas regulatable heat pipes,” Author's Abstract of Candidate's Dissertation, Inst. of Heat and Mass Transfer Author: M. G. Semena.Variable Conductance Heat Pipe, Rotating Heat Pipe, Loop Heat Pipe, Micro Heat Pipe, Nanofluids 1.
Introduction A typical heat pipe consists of a sealed pipe or tube made of a material that is compatible with the working fluid such as Copper for water heat pipes, or Aluminium for ammonia heat pipes. It is a simple construction thatFile Size: 2MB.