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For HVAC systems this paper describes “excellent” acoustics and criteria and tools for acoustic evaluation. Focusing on the HVAC subsystem “air flow”, it further outlines four columns on which acoustic is based. Finally this paper discusses aspects how the vehicle design process which can facilitate acoustic optimization of HVAC systems.

Our field study showed, that more than 50 % of the car drivers have problems in operating the car conditioner correctly. This article gives you an overview of different failures and recommandation how to improve the ease of operation of the control panel.

Computer simulation of the behavior of the automotive cooling system is becoming increasingly common, so as to reduce the dependency on costly testing. The simulation of transient cooling system behavior has become easier with the use of 1-D simulation tools. However, accurate prediction of transient coolant temperature after thermostat operation has been limited by the difficulty in accurately modeling the behavior of the automotive thermostat. Physical models of the thermostat are often inaccurate due to the complexity of the thermostat. Therefore an empirical model has been developed, which can be used to model any automotive thermostat, once a few simple tests have been conducted on the part. This thermostat model can be used in conjunction with a 1-D flow simulation tool to predict coolant transient temperature response during thermostat operation.

A vehicle consumes 15% extra fuel when airconditioning is switched ‘ON’. This extra consumption is due running of engine driven compressor. To overcome this extra fuel consumption and emission of additional exhaust gas to atmosphere, we need to device a system without this engine driven compressor. My paper provides approach towards making use of engine exhaust gas being wastefully discharged to atmosphere. The velocity at which the gas leaves can provide Kinetic energy and its high temperature can be put to the use as Heat energy.

Consistent optimization of low emissions catalyst systems will require appropriate use of alternative substrate geometries. Fundamental heat transfer, mass transfer and friction characteristics provide a solid foundation for evaluating the benefits of these geometries. The purpose of this report is to validate a bench test, based on a previously reported technique, for measuring the fundamental characteristics of catalyst substrates. The sample matrix is subjected to a periodically varying inlet temperature and convective transport properties, reported as Colburn factors, are found by matching the phase shift and amplitude attenuation of the inlet and outlet temperature waves in a finite difference computer program. Flow friction attributes, reported as Fanning friction factors, are found through reduction of measured pressure loss at constant flow rate.

Recent design changes in high pressure diesel injection pumps have increased the heat input to the fuel beyond acceptable levels. This paper will discuss the source of the extra heat, its effects, and various ways of dissipating it. The advantages and limitations of the various methods of fuel cooling are explained.

The purpose of this paper is to recommend the criteria to be considered when selecting thermal insulation to improve the durability of exhaust system components. This paper focuses specifically on the features and benefits of one high temperature insulation alternative, ceramic fiber, and provides a concise comparison against lower performance glass and mineral fiber alternatives.

Description of the design and evolution of a Thermal Component Test Rig capable of simulating the thermal environment normally encountered by the underbody, floorpan, carpeted floors and occupants of automotive vehicles.

The strengths and weaknesses of engine coolants based on organic acid inhibitors are investigated. Recently, this technology has been approved for use by major OEM's. The coolants are expected to have a service life of at least 5 years/160,000 km as compared to the recommended 2 years/48,000 km for conventional silicate inhibited coolants. Laboratory performance tests of commercially available ethylene glycol based coolants and experimental propylene glycol based coolants are presented. These include physical properties measurement, ASTM corrosion tests, compatibility of OA and silicate coolants, tests to stress coolant performance, and electrochemical tests.

This paper presents a lumped parameter method for whole circuit simulation of vehicle cooling systems using the Bathfp simulation environment. The dynamic performance of a 1.8 litre internal combustion engine cooling system is examined. The simulation is compared with experimental data from a test rig incorporating a non-running engine with external heat source and a good correspondence is achieved. The background to the modelling approach is described. It is shown that simulating cooling systems with Bathfp offers the designer the flexibility to assess component sensitivity and changes in system configuration which will aid the process of cooling system optimisation.

This paper presents an investigation of the effect of fouling by considering a tube and plate fin geometry for which performance characteristics are well defined. By matching a particular heat exchanger to a given fan it can be shown that the air-side heat transfer coefficient increases as the air-side passages become progressively blocked, reaching a maximum close to the fully blocked condition. For moderate fouling this increase largely compensates for the change in mean temperature difference brought about by the variation in air flow rate, giving an overall performance very close to that for the clean condition.

The utilization of the exhaust waste heat from engines is now well known and form the basis of many combined heat and power installations. The combination of a thermal power cycle and a refrigerant cycle, however, been the subject of little interest in the past. The paper explores from a theoretical stand point the possibility of utilization of the exhaust gases of a turbocharged Diesel engine as an energy input to a vapor absorption refrigeration system for producing a cooling effect for the combination of pre and inter cooling of the charge air, which is a modified form of the intercooling systems.

The effects are described in aluminum brazing of a phenomenon known as Liquid Film Migration (LFM). This is primarily encountered when -O temper parts are formed and subsequently brazed. If the combination of material homogenization, alloy and cold work is such that the material does not recrystallize totally before the brazing temperature is reached, then the system begins to equilibrate by rapid solid state diffusional processes. These create a moving liquid interface which sweeps from the clad/core interface into the core of the material. This causes significant compositional changes in the volume through which the liquid film passes. Reduced brazeability (filler metal flow) results from the rapid diffusion of silicon into the core. Additionally, a coarse band of intermetallics is formed upon solidification of the enriched liquid zone which can impair corrosion resistance.

The phenomenon of liquid film migration (LFM) in aluminum brazing is described in a companion paper [1]. To clarify the mechanism, the effect of core alloy homogenization, cold work prior to brazing, and brazing temperature on the LFM kinetics has been studied. Based on microstructures, LFM kinetics, and concentration profile data, factors influencing the migration rate of liquid films have been analyzed. Several possible driving forces for LFM are proposed: (1) coherency strain energy, (2) reduction of particle/matrix interfacial energy, and (3) reduction of energy in recovered dislocation structure or subgrain boundaries in the case of lightly cold worked brazing sheet.

The nature and level of the vacuum atmosphere together with the depth and composition of the oxide layer on brazing sheet can have a profound effect on the quality of the brazed joint. For example, magnesium is needed in the furnace atmosphere to obtain a good fillet. However, there is a lack of understanding of the interrelationship between oxide thickness and the amount of magnesium in the furnace atmosphere. This paper attempts to address this area. Samples of brazing sheet with modified oxide layers, some of which simulate storage or transport conditions were brazed with varying magnesium content in the furnace atmosphere. A correlation was made between these two parameters and the material's brazeability. The main conclusion of this study was that if sufficient magnesium is present in the furnace atmosphere the material can tolerate significant changes in oxide thickness and type without sacrificing brazeability.

These days the alignment of radiator and condenser in the vehicle front is the major trend. Due to this alignment, the radiator characteristics are one-sidedly affected by condenser radiating heat, which will cause deterioration in the engine cooling performance at high engine speed and high heat load vehicle operation when air conditioning (A/C) capacity becomes excess. Studies were made on the effects that condenser operation have on radiator characteristics. Results showed that controlling the condenser operation characteristics will provide improved A/C and engine cooling performance in the vehicle system. This paper will discuss the details of the above-mentioned analyses with focus on the vehicle characteristics of front engine, front drive (FF) vehicles and the results of vehicle proving tests.

In the present paper it is shown that fatigue life prediction of a complex spot welded joint must take into account for damage evolution of each spot weld, thus considering the load changes in each spot during damage progression. A method which uses a theoretical stress solution (ERS) is presented and its application is reported both on traditional spot welded joints and on a non trivial joint. Through the use of ERS-N curves the fatigue data performed on different joint geometries can be successfully reconciled.

A theoretical model is developed for crushing of honeycomb structures. Axial crushing is considered for both adhesive bonded and welded honeycombs. The two mentioned cases present different kinematics of collapse; consequently, the Mean Crushing Strength assumes different values. The theoretical model discussed is also able to predict Bar Compressive Strength which is a fundamental variable to be taken into account in the design of energy absorbers for the automotive industry. The analytical results are successfully compared with experimental literature data and numerical results.

Robustness encompasses every aspect of the way in which a 2K (two-part) structural automotive adhesive is made and used, from manufacturing and storage to dispensability, adaptability to different substrates and stamping lubricants, cure characteristics, strength, and durability. Illustration of the many facets of adhesive robustness are made using primarily 3M #5047, a 2K epoxy hem flange adhesive developed for bonding oily untreated metals. Areas of robustness covered include storage stability, surface oil accommodation, open time, and performance under various curing conditions. The recent introduction of adhesives having unique mix ratio control and NDT capabilities heralds new levels of adhesive robustness.

Global manufacturing has the individual automotive component plants, on virtually all continents, scrambling for the “edge” to be the most competitive manufacturer and thus be the producer of choice. To be competitive in price and quality and that over “the long haul” is a tall order, indeed. A lot depends on the machining processes producing the components that, assembled, make up the powertrain. While outsourcing other automotive parts might be the right economical and technological choice, to produce ones own engines and transmissions is still one of the areas of true “value adding” and also a matter of the manufacturer's image. Hence the industry's effort to offer ever better, more potent families of engines and transmissions. New, advanced machining processes have evolved recently, that make manufacturing more productive and predictable. The three areas most promising are: One-pass finish-machining High-speed machining (Near) Dry-machining