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A universal autonomous controlled heat transferring module on base of two-phase loop with capillary pump have been elaborated. This module consists of one evapourator and one radiator-condenser. Various variants for suggested module control by using of active or passive elements, providing the CPL start-up, restarting and temperature regulation, have been considered. There is determined a structure concept and recommendations on mathematical modeling of Thermal Control System (TCS), made on base of several controlled heat transferring modules with capillary pumps, are given. There are given results of computer experiment with mathematical model of artificial Earth satellite payload TCS. This TCS consists of four controlled, independent in power supply, CPL, which start-up and control are carried out by using of passive devices.

The approarch to utilization of software HEAT'90 to thermal simulation of heat pipes and units of their connections with elements of thermal control systems is presented. The application of finite elements method for solution of problems, interective regime of functioning “software-user” allow to simulate enough complicated 2-D constructions and transfer processes by user without special programme languaege knowledge and trainig. The examples of software employment are discussed like next: efficiecy of flange unit in heat pipe input/output zones; influence of dried grooves presence on temperature field in cross-section; distribution along pipe length; efficiency of unit “heat pipe-honeycomb radiator” and other. The main development of software for elements of thermal control systems design application are shown.

A capillary pumped two-phase ammonia heat transport loop, developed at Lavochkin Assoc., Moscow, was tested under laboratory conditions at ERNO, Bremen. The tubular capillary pump evaporator contains a sintered Nickel powder body with a small pore size of 1. 5 μm. The line diameter of the vapour and the liquid line is only 6 mm and 4 mm, respectively, allowing an easy accomodation to any architecture in the filled state. The objective of the test was to determine the heat transport performance of the loop under different orientations w.r.t. gravity under steady state and transient, in particular priming load conditions. The tests have demonstrated a large heat transport performance of more than 1100 W in a vertical orientation, where the evaporator was located 2 m (!) above the condenser. The priming ability appears to depend on the load timeline as well as on the orientation.

The results of experimental and analytical investigation of startup regimes of CPLs are presented. The experimental data upon change of temperatures and pressures in the loop during the startup process in the loop are adduced. The model of a startup is formulated and the analysis of conditions realizing reliable startup is fulfilled.

In the frame of an ESA technology program, the development of a High Capacity Grooved Heat Pipe (HGP), based on the thermal requirements of the next generation of telecommunication satellites, was contracted to SABCA. Different promising concepts and methods of groove technology were reviewed. A trade-off and design study was performed on potential HGP concepts, taking into account theoretical performances (on earth and in micro-gravity), ease of manufacturing and of assembly as well as the heat pipe working reliability and priming capability. The two finally selected concepts were aluminium extruded heat pipes (outer diameter of 25 mm, vapour core diameter of 15 mm), based on a multi re-entrant grooves concept or on a mixed rectangular/re-entrant grooves concept.

The use of carbon fiber reinforced composite materials in unit-carrying satellite radiator panels was studied. Different panel architectures and component materials were identified. The mass-specific heat rejection capability of the most promising of these configurations was analytically determined for different heat loads having either the stiffness or the strength of a reference configuration. The analytical results clearly define the optimum panel configuration under the different structural and thermal requirements. The panel configuration consisting of carbon fiber reinforced plastic (CFRP) facesheets, aluminium honeycomb core and top-mounted aluminium heatpipes was found to be superior in a wide range of requirements and therefore selected as a reference concept. A flexible adhesive was used as the thermal interface between both components having significantly different thermal expansion coefficients.

Automotive technologies such as fuel injection, anti-lock braking systems and automatically adjusting suspension systems have created a need for soft magnetic alloys having good corrosion resistance and fabrication characteristics, but with higher saturation flux density (Bs) and more consistent magnetic performance than ferritic stainless steels. This paper will describe the development of a family of controlled chemistry Chrome Core™ * alloys specifically designed for use in magnetic components where corrosion resistance substantially superior to that of pure iron, low carbon steel and silicon-iron alloys is required without the substantial decrease in saturation flux density and inconsistent magnetic response associated with conventional ferritic stainless steel.

Alternative materials to the present terne (hot-dip lead-tin) coated steel are required for fuel tank compatibility with future flexible fuel blends of methanol and gasoline. In addition, the alternative materials must be more resistant to external corrosion from road salts than the present terne coated steel. The goal of the study described in this paper was to identify a coated steel that will satisfy these requirements. Materials evaluated included organic coatings over terne, galvanneal, and zinc-nickel coated sheet steels. The fuel resistance of these materials was evaluated by exposure to various flex fuel blends at elevated temperature. The external corrosion performance of these coatings was examined by exposure to salt spray and cyclic corrosion laboratory tests. The results of these tests are described in terms of resistance to paint delamination, red rust formation at scribes, cut edges, and deformed areas.

Cosmetic corrosion of painted automotive substrates is a complex phenomenon being a function of number of environmental variables and material properties. To address the need for reliable accelerated corrosion tests, a high performance corrosion chamber was built by VOLVO car corporation, Gothenberg, Sweden. Using a statistically designed program of experiments, excellent correlation between outdoor and laboratory simulations have been established using the VOLVO technique. Traditional methods for corrosion data analysis has been based on the use of well known statistical methods. In this paper, we have introduced Artificial Neural Networks (ANN) to study and establish complex relations between scribe creep data and the variables that govern cosmetic corrosion performance. Application of the ANN methodology as a predictive tool has been discussed.

Cosmetic corrosion resistance of coated and cold rolled steel sheet products is being determined by use of test coupons (paint panels) mounted on full-size pickup trucks operating in the severe corrosive environments of Montreal, Quebec and St. John's, Newfoundland, Canada, Ten standard materials from the joint AISI/SAE corrosion test development program, including hot-dip galvanized, galvannealed, electroplated zinc and zinc-nickel alloy-coated, as well as phosphated and unphosphated cold rolled steel have been under evaluation for five years. The results of these evaluations are described in terms of resistance to paint undercutting (creepback) and red rust staining at scratches (scribes) through the paint film to the steel substrate. The effects of horizontal and vertical test coupon orientations are considered. Performance of the materials in this evaluation provides an excellent standard of real-world behavior against which the reliability of accelerated tests can be determined.

During the last decade many materials were developed to improve corrosion resistance of automotive vehicles as to cosmetic and perforation corrosion. Tests were carried out based upon classic laboratory salt spray testing as well as on newly developed cyclic laboratory tests and on vehicle tests. To translate the laboratory test results into practice it is necessary to understand the corrosion mechanisms occuring in laboratory experiments compared to the corrosion mechanisms in real practice. This paper deals with the understanding of laboratory corrosion mechanisms in cyclic corrosion testing compared to some static outdoor corrosion tests. It is shown that delamination rate of scribed panels of painted hot dip galvanized, and galvannealed materials is highly controlled by the speed of anodic dissolution of the “zinc” due to the electrical characteristics of the corrosion products formed in the scribe and under the paint layer. These characteristics depend on the type of test.

An extensive atmospheric corrosion test program to simulate automotive field conditions has been successfully completed. This paper focuses on the corrosion results from the widely exposed AISI set of correlation panels for cosmetic corrosion. Eight factorially designed 12-week tests have been performed in the laboratory, using high performance test equipment, capable of simulating diverse outdoor conditions. The results have been compared with those of outdoor scab exposures and reference panels on vehicles, running in Canada and Sweden. The influences of six corrosive test variables on the response creep-back from scribe on the painted panels are demonstrated, based on a statistic evaluation of the test matrix. All higher settings of the introduced accelerating test variables have each resulted in a decrease in the test correlation with on-vehicle exposures.

Exterior automotive trim materials are exposed to aggressive environments and therefore must have satisfactory corrosion resistance. Stainless steel materials such as bimetal (stainless steel clad aluminum) are therefore used extensively in this application. This paper addresses the effect of surface contamination on the corrosion behavior of stainless steels which have been fabricated with the application of a PVC polyfilm protector. The effect of residual deposits on the stainless steel has been investigated using CASS and cyclic immersion corrosion tests, Auger analysis, and gas chromatography coupled with Fourier Transform Infrared Analysis (FTIR). The mechanism of reduced corrosion resistance attributed to these residual deposits is described.

The American Iron and Steel Institute's (AISI) Task Force on Automotive Corrosion is making significant progress in its continuing efforts towards development of an accelerated laboratory test for ranking the cosmetic corrosion resistance of automotive steel sheet products. This paper provides an overview of this work and reviews major accomplishments to date. Accelerated tests conducted by the AISI and by the SAE's Automotive and Corrosion Prevention Committee (ACAP) Division 3 are compared to long-term on-vehicle exposure tests now in progress for four years in Montreal, Quebec and St. John's Newfoundland. A license-plate exposure test has also been initiated to broaden the basis for real-world performance. Statistical methods for comparing the results of the various tests are described. A designed experiment (Plackett-Burman L8) is underway to evaluate the effects of seven key cycle test parameters on the rankings of the test materials in a laboratory cyclic corrosion test.

In cold and heavy snowfall regions such as Europe and North America, substantial quantities of rock salt are spread on roads for the prevention of icy road surfaces and car slipping so that winter transportation can be assured. Such salt however promotes corrosion not only of automotive bodies but also of automotive parts. Automotive piping is no exception, leading to the need for new surface treatment. With a view toward finding a promising substitute for Zn plating which has been used for many years, various high corrosion resistance surface treatments have been compared. This paper reports the results of the comparison.

Cadmium has been identified by the United States Army's Tank and Automotive Command as a threat to worker health and the environment. Based on already completed cadmium substitute testing, an evaluation program was conducted to quantify the performance of environmentally acceptable, multi-layer coatings that could be directly substituted for cadmium on threaded fasteners. The performance issues investigated included coating system lubricity and corrosion control performance. Data were generated from both natural marine atmosphere exposure tests and laboratory evaluations. Test specimens were prepared by applying sacrificial plating layers and lubricous topcoat materials to commercially available 1/2-20 UNC Fine, Grade 5 fasteners. Experimental analyses included realistic torque-tension curve development, marine atmosphere exposure testing, and ASTM B 117 salt fog evaluations.

In this study Al-Si-Mg alloy sheets containing various amounts of Si and Mg were subjected to an anodic electrolysis test, and the relationship between intergranular corrosion susceptibility and addition of Si and Mg in aluminum alloy was investigated. Generation of intergranular corrosion was determined by both composition of alloy and temperature of heat treatment and was considered to accelerate when Mg2Si particles percipitated on grain boundary.

For the last few decades PVC-plastisols have been one of the most common process materials in the automotive production used as adhesives, sealants or for various coating processes. A high standard of performance has been reached. But recently raised concerns about chlorine containing substances created in fire and combustion arose search of alternatives to PVC-products. Intensive work led to various possibilities to substitute today's PVC-plastisols by using polymers free of halogens. As a main target, concentration was given to similar technical performance as well as to same easy application as with PVC-plastisols. Although investigations referring to polyurethanes gave excellent technical results the price/performance ratio was rather unacceptable. For some applications plastisols based on pure acrylic ester (co)polymers are very valid substitutes especially for body-in-white purposes. But for paint shop applications the cost for the basic raw material was seen to be too high.

Increasing service-life requirements for automobile and truck exhaust system components and the problem of potentially severe corrosivity of cold-end exhaust system condensate have greatly increased interest in the use of advanced construction materials for cold-end components. Studies on dynamometer test systems have shown that condensate can exhibit relatively high soluble salt content and variable pH ranging from mildly alkaline to appreciably acidic depending mainly upon driving conditions, catalytic converter mode of operation, air/fuel ratio and fuel chemistry. In these circumstances, there is considerable interest in determining the advantages afforded by aluminized stainless steel and various grades of stainless steel as construction materials. The primary goal of the present study was to achieve realistic relative materials behavior in laboratory testing by simulating realistic chemical/physical muffler environmental conditions.

Alcohol-blended fuel is receiving increasing attention for its ability to provide cleaner automotive exhaust gas. Alcohol-blended fuel is however more corrosive than conventional gasoline and tends to corrode the materials of a fuel system. Use of nylon tubes or stainless steel tubes is now studied but is still accompanied by the unsolved problems of gas penetration and higher cost. As a technique pertaining to alcohol-blended fuel, single-wall tubes having excellent corrosion resistance have been developed by forming a Ni-base double plating layer on the inner walls of fuel pipes. Their corrosion resistance was evaluated using alcohol-blended fuel and the like.