Downsizing is one of the crucial activities being performed by every automotive engineering organization. The main aim is to reduce – Weight, CO2 emissions and achieve cost benefit. All this is done without any compromise on performance requirement or rather with optimization of system performance. This paper evaluate one such optimization, where-in radiator assembly with two electric fan is targeted for downsizing for small commercial vehicle application. The present two fan radiator is redesigned with thinner core and use of single fan motor assembly. The performance of the heat exchanger is tested for similar conditions back to back on vehicle and optimized to get the balanced benefit in terms of weight, cooling performance and importantly cost. This all is done without any modification in vehicle interface components except electrical connector for fan. The side members and brackets design is also simplified to achieve maximum weight reduction.
A new appraisal of the thermomechanical behaviour of a hybrid composite brake disc in a formula vehicle Research Objective This paper presents a hybrid composite brake disc with reduced Un Sprung Weight clearing thermal and structural analysis in a formula vehicle.Main purpose of this study is to analyse thermomechanical behaviour of composite brake disc for a formula vehicle under severe braking conditions. Methodology In the disk brake system, the disc is a major part of a device used for slowing or stopping the rotation of a wheel. Repetitive braking of the vehicle leads to heat generation during each braking condition. Based on the practical understanding the brake disc was remodelled with unique slotting patterns and grooves, using the selected aluminium alloy of (AA8081) with reinforcement particle of Silicon carbide (SiC) and Graphite (Gr) as a hybrid composite material for this proposed work.
The efficiency of ICEs is strongly affected by the heat losses of exhaust gases and engine cooling system, which account for about 60% of the heat released by combustion. Several technologies were developed to recover waste heat in ICEs, from turbochargers to ORCs, Stirling cycles and piezoelectric generation. A promising approach is to transfer the waste heat to a fluid, like water, and inject it into the combustion chamber. In such a way, the recovered energy is partially converted into mechanical work, by improving both engine efficiency and performance. In this work, the engine benefits obtained by using supercritical water as the vector to recover heat losses are analysed. Water has been chosen since it has a relatively high heat capacity and can be extracted directly from exhaust gases. A quasi-dimensional model has been implemented to simulate the ICE work cycle. Specifically, in this paper a spark ignition ICE, four-stroke with port fuel injection (PFI) has been considered.
The potentiality of knock mitigation by means of the control of the coolant flow rate is investigated. As a first step, the dynamic behavior of the wall temperature in response to a sudden variation of the coolant flow rate is analyzed experimentally in a small displacement, 4-valve per cylinder SI engine, which is equipped with an electrically driven pump. Subsequently, the influence of the wall temperature on knock onset is analyzed through a zero-dimensional model and the Livengood and Wu integral. Finally, an experimental activity on the engine test bed is carried-out in order to evaluate the influence of the coolant flow rate and of the engine inlet coolant temperature on the knock phenomenon. Results show that, even though a retarded spark advance and a mixture enrichment are not avoidable in the early stage of knock onset, a cooling control can help reducing the time of use of these fuel consuming strategies in the case of prolonged high-load conditions.
The efficient operation of test benches within the framework of research and development projects directly correlates with the "health" of the examinee to be investigated. The use of so-called Early Damage Detection Systems (EDDS) is becoming increasingly popular for reasons of Unit Under Test (UUT) monitoring. In the context of this publication the expectations of an EDDS and its structure are discussed as well as its advantages and disadvantages in test bench operation analyzed and compared with the results of measurements. The used EDDS should primarily prevent the damage, up to the loss of the test object by a total loss, in order to ensure a finding possibility of the damaged part at the examined test object. A deviation of the test object behavior from the undamaged condition must be recognized in an early status and must lead to a shutdown of the test bench operation after reaching a defined limit value.
In the last years, the increase of the specific power of the modern engines has required a parallel improvement of the performances of the cooling system. In this context, also the control of the oil temperature has become an important issue, leading to the introduction of dedicated cooling circuits (air-cooled or liquid-cooled). Among the two, the liquid-cooled solution results in a more compact installation in which the oil-to-liquid heat exchanger is directly mounted on the engine block and integrated in the engine cooling system. It is clear that, in a liquid-cooled solution, the design of the heat exchanger represents an issue of extreme concern, which requires a compromise between different objectives: high compactness, low pressure drop, high heat-transfer efficiency. In this work, a computational framework for the CFD simulation of compact oil-to-liquid heat exchangers, including offset-strip fins as heat transfer enhancer (turbolator), has been developed.
Due to its high benefit-cost ratio, decreasing mechanical friction losses in internal combustion engines represents one of the most effective and widely applicable solutions for improved engine efficiency. Especially the piston group – consisting of piston, rings and pin – shows significant potential for friction reduction, which can be evaluated through extensive experimental parameter studies. For each investigated variant, the steady-state friction measurements are fitted to an empirical polynomial model. In order to calculate the associated fuel consumption and CO2 emissions in transient driving cycles, the steady-state friction model is used in a map-based vehicle simulation. If transient engine operation entails friction phenomena that are not included in the steady-state model, the simulation could yield erroneous fuel consumption and CO2 predictions.
Global automotive fuel economy and emissions pressures mean that 48V hybridisation will become a significant presence in the passenger car market. The complexity of the powertrain solutions is increasing in order to further increase fuel economy for hybrid vehicles and maintain robust emissions performance. However, this results in complex interactions between technologies which are difficult to identify through traditional development approaches, resulting in sub-optimal solutions for either vehicle attributes or cost. This paper presents the results from a simulation programme focussed on the optimisation of various advanced powertrain technologies on 48V hybrid vehicle platforms. The technologies assessed include an electrically heated catalyst, an insulated turbocharger, an electric water pump and a thermal management module (a coolant valve replacing a conventional thermostat).
This SAE Aerospace Standard (AS) establishes the requirements for 37° flared tube fittings or machined internal cone fluid connection fittings for use with 37° external cone, spherical nose and seal ring fittings in all types of aerospace fluid systems (see Section 6).
This specification covers the requirements for inspection of ground chromium plated surfaces for grinder-induced damage to the chromium plate and substructure. The specification also provides users with criteria for distinguishing between such damage and acceptable indications inherent to the chromium plate.
This SAE Aerospace Information Report (AIR) provides technical information to assist the development of specific cleaning methods for filter elements. Consideration is limited to filter elements which are designated as "cleanable" (not "disposable"), but which cannot be cleaned by simple and obvious procedures. Cleaning methods developed according to this report should be evaluated by the methods of ARP725. Satisfactory cleaning methods can be developed for most "cleanable" filter elements. Technical or economic feasibility of the cleaning method may be limited, however, by incompatibility of filter-element construction materials, by mechanical weakness or lack of corrosion resistance to withstand repeated or continued cleaning, or by the presence of unusually tenacious contamination. These factors must be considered when selecting approaches to the development of specific methods.
This specification, in conjunction with the general requirements for steel heat treatment covered in AMS2759, establishes the requirements for heat treatment of low-alloy steel parts to minimum ultimate tensile strengths of 220 ksi (1517 MPa) and higher. Parts are defined in AMS2759. The requirements for heat treatment of alloy Aermet100 are no longer part of this specification and can be found in AMS2759/3. Due to the limited hardenability of these materials, size limits have been added to this specification.