Raj Kumar Mandloi, Professor & Head of Mechanical Engineering Department of M. A., National Institute of Technology, delivers a speech at Track C World Forum on Intelligent Manufacturing Industry of the 2nd WORLD EMERGING INDUSTRIES SUMMIT (WEIS 2013)

“ How to achieve better fuel economy and less emission with proper thermal management design of duel fuel automotive engines”

By Prof. R. K. Mandloi

Mechanical Engineering Department

M. A. National Institute of Technology

►    Introductio

Ø  Engine cooling optimization is attracting the attention of researchers as a means of making engines comply with increasingly stringent demands for lower fuel consumption and lower exhaust emissions.

Ø  The conventional objectives of engine cooling optimization have to satisfy material durability requirements and prevent abnormal combustion, automotive engineers are now focusing on the additional benefits of engine cooling, such as improvement of engine output through intense cooling and improving fuel consumption.

Ø  In the present scenario the designs of S I engine being used in automotives by various manufacturers are not properly suitable to Indian climatic condition (Tropical Regions). This country is among tropical countries where the variation in the ambient temperature is having very vast range i. e. from 0oC to 50oC in various regions of the country.

Ø  The development of engines with its complexity of in-cylinder processes requires modern development tools to exploit the full potential in order to reduce fuel consumption. Looking in to this vast varying ambient temperature rang it is very difficult to say that which temperature is most suited to operating condition of engines with proper heat rejection and gives best performance levels as for as SFC & BP is concerned.

Ø  Satisfactory engine heat transfer is required for a number of important reasons, including material temperature limits, lubricant performance limits, emissions, and knock.

Ø  Since the combustion process in an internal combustion engine is not continuous, the component temperatures are much less than the peak combustion temperatures.

Ø  Heat transfer to the air flow in the intake manifold lowers the volumetric efficiency, since the density of the intake air is decreased.

Ø  The heat transfer rate in an engine is dependent on the coolant temperature, the engine size, and subsequent atmospheric temperature among other variables.

Ø  There are complex interactions between various operational parameters. For example, the temperature of the engine coolant decreases, the heat transfer to the coolant will increase, and the combustion temperature will decrease.

►    Tackling climate change and improving energy efficiency are two of the major challenges currently facing transport policymakers around the world.

►    In this context, the development and introduction of EFV’s (Environmental Friendly Vehicles) as well as renewable fuels are the main fields of action.

►    This issue concerns us all: the government, the industry, the research community and the consumers. Nobody can and must shirk from the responsibility for protecting health and climate change especially with regard to safeguarding the systems for future generations.

►    Energy efficiency refers to products or systems designed to use less energy for the same or higher performance than regular products or systems.

Ø  After reviewing the literature and applying previous experiences through experimental, investigations & observations the Engine Systems can be optimized & evolved to provide precision cooling with necessary changes in Engine operational settings and cooling system  to reduce excessive heating & irregular temperature gradient across the cylinders of the engine.

Ø  In this work, it has been tried to investigate and validate the best option to run the SI engine and simultaneously maintaining the emission norms. There are many strategies for improving fuel economy and reducing exhaust emission by varying operating temperature.

Ø  The experimental study is carried out on a three cylinders, four stroke, petrol, water cooled car engine test rig connected to eddy current type dynamometer to validate the effect of higher environmental temperature.

Ø  The results are shown by various graphs with effect of engine temperature on specific fuel consumption, brake power, engine speed, engine load and emission levels of Nox, HC, CO for gasoline and LPG to improve fuel consumption.

►    Agenda: Improving the Spark-Ignition Engine

Ø  The biggest opportunity for improving the spark ignition engine is boosting, turbo-charging and downsizing.

Ø  Stoichiometric operation enables very low air pollutant emissions.

Ø  Many other design variables could contribute: e.g. increase compression ratio, variable valve control, lower friction, reducing throttling losses.

Ø  The major challenge is controlling knock.

Ø  20 - 30% higher part-load efficiency plausible.

Ø  Higher octane (e.g. premium) gasoline.

Ø  With VVT, delay intake valve closing, lean operation vs. stoichiometric.

Ø  Homogeneous gasoline direct injection and downsizing.

Ø  Variable compression ratio engine.

Ø  Increase mixture octane with H2 plus CO from on-board reformer.

►    Important Engine Performance Parameters

Ø  Specific Fuel Consumption: Specific fuel consumption is defined as the amount of fuel consumed per unit of power developed per hour. It is clear indication of the efficiency with which the engine develops power from fuel.

Ø  Brake specific fuel consumption (bsfc) is determined on the basis of brake out put of the engine while indicated specific fuel consumption (isfc)  is determined on the basis of indicated out put of the engine.

Ø  Brake Power: The power developed by en engine at the out put shaft is called the brake power (B.P.). The measurement of power involves the measurement of force (or torque) as well as speed. The power is done with the help of a dynamometer and torque is by a tachometer or by some other suitable device.

►    Combustion & Temperature in S.I. Engines

         Combustion may be defined as a relatively rapid chemical combination of hydrogen and carbon in the fuel with the oxygen in the air resulting in liberation of energy in the form of heat. The conditions necessary for combustion are:

Ø  The presence of combustible mixture. 

Ø  Some means of initiation combustion.

Ø  Stabilization and propagation of flame in the combustion chamber.

Ø  A chemical equation for combustion of any hydrocarbon can be easily written, for C18H18 (iso octane) the equation is

         C18H18 + 12.5O2 = 8CO2 + 9H2O

Ø  Temperature control is very important for combustion engines as temperature is a critical factor both for chemical reactions and mechanical stresses.

Ø  Traditionally, temperature control is performed by feedback of a global quantity, the coolant temperature, which is a poor indicator of specific temperatures.

Ø  The use of electrical pumps opens flew possibilities for thermal control, in particular in terms of efficiency, especially in the cold start phase. Shows that predictive control and the use of electrical coolant pumps allow to regulate specific temperatures.

Ø  The successful ""precision-cooled"" prototype engines have been demonstrated, the design of most mainstream coolant jackets has evolved only cautiously, and lacked this major change in approach.

Ø  The achievements and potential of precision cooling are reviewed, along with an extension into nucleate-boiling-based heat transfer.

Ø  It is demonstrated that ideas for advanced ""external"" cooling systems with low flow rates are in fact extremely compatible and with the ""internal"" precision engine cooling philosophy, and in combination promise even larger benefits.

►    Temperature in S.I. Engines

 Temperature control is very important for combustion engines as temperature is a critical; factor both for chemical reactions and mechanical stresses.

►    Fuel Economy for Gasoline Engines

►    The increase in fuel consumption during engine warm-up can be attributed to several factors, such as: increased friction associated with cold lubricant, degradation of the lubricants by condensate and unburned fuel, less efficient combustion in a cold combustion chamber as a result of the heat transfer from the burning air-fuel mixture to the cold combustion chamber walls.

►    Also, the cold combustion chamber walls lead to increase quenching  of the  flame  front  in  the  thermal  boundary  layers  and  the corresponding increase  of the hydrocarbon,  carbon monoxide emissions  and  fuel consumption.

►    The induction system parts in contact with air-fuel mixture are cold and can't supply the heat needed to vaporize the sufficient quantity of fuel.

►    Therefore to compensate the decrease in the fuel vaporization an excess fuel is supplied. Several sources lead to hydrocarbon and carbon monoxide emissions during engine warm-up namely created by poor fuel vaporization and cold catalytic emission system.

►    Further, during engine warm-up the friction and the heat losses are greater than once fully warmed and the time required to reach steady-state operating temperature is longer. These factors contribute to a longer period of relatively poor combustion and consequent need for more fuel enrichment.

►    The control strategies of the variable valve timing and the intake pressure were clarified to keep auto-ignition at a light load and prevent knock at a full load.

►    There are many control strategies in engine control to improve fuel economy and reduce exhaust emissions, including the following;

►    Gasoline engine: variable valve timing, improved ignition systems, adapted boost, direct injection stratified charge, controlled combustion, cylinder deactivation, divided chamber stratified charge are included.

►    In direct injection gasoline engine combustion takes place at a stoichiometric contour, generating the highest temperature the fuel can attain with air, irrespective of the air fuel ratio in the cylinder.

►    One of the most expedient routes to improving in-vehicle fuel economy is to reduce the swept volume of an engine and run it at a higher BMEP for any given output.

►    This can be achieved through pressure charging. However, for maximum fuel economy, particularly at part load, the compression ratio (CR) should be kept as high as possible.

►    This is at odds with the requirement in pressure charged engines to reduce the CR at higher loads due to the knock limit. It has been studied a pressure charging system which will allow a high compression ratio to be maintained at all times.

►    Alternative Gaseous Fuels

►    The most common of the alternative fuels is natural gas that is usually made available after processing as “pipeline processed natural gas”. It is supplied for engine applications normally as compressed natural gas, (CNG), or occasionally in its cryogenic liquid form, (LNG).

►    However, after it’s processing when destined for transport to its ultimate consumption points its composition becomes less widely variable and made up mostly of methane.

►    Accordingly, much of the work and information available relating to natural gas as an engine fuel consider methane to be an adequate representation of the whole fuel.

►    Another common source of gaseous fuels involves the higher molecular weight components of natural gas in the form of Liquefied Petroleum Gases, (LPG), which can be liquefied under pressure at ambient temperature.

►    The very wide diversity in the composition of the gaseous fuels commonly available and their equally wide variety of their associated physical, chemical and combustion characteristics make the prediction and optimization of their combustion behavior in engines a more formidable task compared to conventional liquid fuels.

►    Continued research is needed to provide more light on their suitability as engine fuels and understand better the roles of the many factors that control their behavior so as to achieve in practice the many potential superior benefits associated with their applications as engine fuels.

►    Process & Technology Status – Internal combustion engines running on liquid petroleum gas (LPG) are well-proven technologies and work much like gasoline-powered spark-ignition engines. Natural gas (NG) engines are also well-proven. They are typically used as spark-ignition engines for bi-fuelled (gasoline/CH4) cars, in combination with gasoline.

►    Performance & Cost – Bi-fuel LPG cars can reduce greenhouse gas (GHG) emissions by 15% as compared to petrol operation. NG cars can achieve GHG reductions of up to 25%. The energy efficiency of engines running on natural gas is generally equal to that of gasoline engines. When running on LPG or NG, CO2 emissions are at least 10% or 20% lower, respectively, if compared to gasoline.

►    Potentials & Barriers – In 2008, more than 7 million Natural Gas Vehicles (NGVs) were on the roads, most notably in Argentina, Brazil, Pakistan, Italy, India, China, and Iran, with South America leading the global market with a 48% share. The number of LPG/NG kits sold globally is estimated to reach 8.0 million by 2012. An appropriate infrastructure, along with governmental support, may accelerate the growth of LPG and NG as global alternative fuels.

►    Octane Quality and knock

►    The one obvious route to improve performance of the spark ignition engine is to increase engine compression ratio.

►    With increase in engine compression ratio however, knocking combustion occurs that can cause engine overheating, loss in efficiency and increase in emissions.

►    Persistent knocking can lead to mechanical damage to engine components under high load operation.

►    High antiknock quality of gasoline is needed to prevent or minimize knocking combustion in high compression ratio SI engines.

►    The resistance of fuel to knock is defined by the fuel octane number (ON). This is a numerical scale generated by comparing knocking combustion characteristics of the fuel to that of standard reference fuels in a standardized test engine.

►    The higher the octane number of fuel less likely it will auto-ignite and give knocking combustion.

►    Effect of Spark Timing

►    The effect of the spark timing on the engine’s heat losses at different equivalence ratios, advancing the spark timing causes an increase in the percentage of heat losses, because advancing the spark causes the combustion to be completed within TDC, hence, more time would be available for the combustion products to lose heat to the surroundings.

►    The percentage heat loss increases as the mixture is enriched, reaching its peak at mixtures within stoichiometry, because of the higher thermal energy released.

►    This situation drastically changes at richer than stoichiometric mixtures because of the poor combustion. Further, that the greater the spark advance the greater the tendency of the engine to knock, represented by knocking index (KI).

►    Effect of Compression Ratio and Spark Plug Location

►    The effect of the compression ratio and spark plug location on the percentage heat loss can be clearly seen that increasing the compression ratio increases the percentage heat losses due to increased overall cylinder temperature and the near-TDC completion of combustion.

►    Further, shifting the spark plug location from the edge towards the centre reduces the percentage heat losses as it reduces the flame travel path and hence reduces the combustion duration.

►    This is valid up to compression ratios of 9.0, beyond which, due to knocking a higher rate of energy release causes a higher percentage of heat losses to the surroundings.

►    Effect of Combustion Duration and Flame Speed

►    The lengthening the combustion duration or lowering the flame speed causes an increase in the heat loss since the products of combustion have more time to lose some heat to the surroundings.

►    This effect dominates at lower engine speeds, perhaps due to lesser turbulence inside the cylinder.

►    This is believed to be due to the suppression of the dissociation of certain products of combustion (like CO2 and H2O) and variable specific heat losses.

►    Effect on Engine Power and Load

►    The effect of percentage heat losses on engine power can be explained that the decrease in the percentage heat losses increases the engine pressure and temperature.

►    The analytical study showed that engine design and operating parameters have an effect on the percentage heat losses from the engine.

►    Increasing compression ratio, the need for near central spark locations, larger valve areas and the aim for leaner air–fuel equivalence ratios to have a favorable effect on reducing heat losses, though care must be taken to avoid knocking.

►    It can be concluded that the Increase in percentage heat losses reduces the cylinder peak pressure and temperature, causing the engine power to drop because a lesser fraction of the thermal energy ends up as useful work.

►    Heat Transfer in I. C. Engine

►    Satisfactory engine heat transfer is required for a number of important reasons, including material temperature limits, lubricant performance limits, emissions, and knock.

►    Since the combustion process in an internal combustion engine is not continuous, the component temperatures are much less than the peak combustion temperatures.

►    Heat transfer to the air flow in the intake manifold lowers the volumetric efficiency, since the density of the intake air is decreased.

►    The heat transfer rate in an engine is dependent on the coolant temperature and the engine size, among other variables. 

►    The Effect & Features of Engine-Cooling System

         While convectional engine-cooling system is adopted for their simplicity & reliability in protecting the engine, a cooling system has the additional goal of improving engine fuel economy & emissions.

         This is achieved through a fine balance between the three main factors bridging the engine-cooling system to fuel efficiency & emissions, which are: -

►    Frictional losses within the engine.

►    Auxiliary power requirement to operate the cooling system.

►    Combustion system boundary conditions, such as combustion-chamber temperature, charge density & charge temperature.

►    In an engine-cooling system, these factors can be influenced by the cooling system without compromising the operating limits on the engine structure, a characteristic uncommon in convectional systems.

►    These features enable an advanced engine-cooling system to positively influence the element that link the engine-cooling system to engine fuel efficiency & emissions output with greater system effectiveness & operational stability.

►    With multiple constraints on the performance of the engine, it is not possible to improve all aspects of the engine performance by just manipulating a single variable or aspect of the cooling system.

►    Engine Energy Distribution

►    Shaft Power: 25-40%

►    Heat Rejection:

§  Coolant Heat Rejection: 10-35%

§  Exhaust Enthalpy Loss: 20-45%

§  Engine External Surfaces: 2-10%

►    Engine Warm Up

§  Combustion chamber: 1 minutes

§  Engine Block: 20 minutes

§  Engine Compartment: Up to 1 hours

►    Heat Transfer in Exhaust

►    Exhaust temperature:

§  SI: 400-600oC

§  CI: 200-500oC

►    Heat Transfer in Combustion Chambers

►    Radiation:

§  SI: Approximately 10% of Total

§  CI: Approximately 20-35% of Total

§  Carbon Particles are good radiators

►    High Temperature Corrosion

►    Degradation by high temperature corrosion is of major concern in many industrial processes and energy conversion systems-chemical and process plants of various types, furnaces, boilers, engines, incineration plants, gas turbines and in certain types of nuclear plants. Thus high temperature corrosion is a dominant technological problem and its prevention processes is a significant challenge. In general, there are four modes of degradation associated with the processes of high temperature corrosion:

►    Surface scaling- direct corrosion of metal to corrosion products leading to decreased cross-sectional area and thus load-bearing capacity.

►    Internal degradation – formation of particle and/ or particulates within the alloy reducing cross-section area and involving mechanical failure mechanisms, e.g. fatigue.

►    Surface scale spallation – associated with scale growth stress and stress generated during thermal cycling.

►    Corrosion product vaporization – involves loss of protective scale leading to the depletion of the elements required for the formation of the protective layer by selective oxidation/ sulphidation.

►    Engine Cooling Systems

►    There are two types of engine cooling systems used for heat transfer from the engine block and head; liquid cooling and air cooling.

►    With a liquid coolant, the heat is removed through the use of internal cooling channels with in the engine block. Liquid systems are much quieter than air systems, since the cooling channel absorbs the sounds from the combustion process. However, liquid systems are subject to freezing, corrosion, and leakage problems that do not exit in air system.

►    The performance of the engine-cooling system has steadily improved as the power output & density of internal combustion engines gradually increases.

►    With greater emphasis placed on improving fuel economy & lowering emissions output from modern IC engines, engine downsizing & raising power density has been the favored option.

►    With increasingly compact engine design & higher specific power, the density of the waste heat generated has increased significantly. Removing heat from an increasingly restricted space is a particular concern at vulnerable region, such as the exhaust –valve bridge area, as the risk of catastrophic failure in such regions is increased, even with minor failure in the cooling system.

►    This heat rejection problem which is prominent at wide open throttle (WOT) conditions is tackled by optimizing coolant gallery design for optimum heat transfer effectiveness by targeting this region with high coolant-flow velocities.

►    Cooling system is evident at part – load conditions in convectional engine-cooling system because of the engine driven coolant pump, which supplies less than required coolant flow in the system.

►    The current engine-cooling system is a passive system, the engine management system controls the heat distribution in the engine & vehicles by compensating engine controls, such a spark timing & air fuel ratio to regulate engine power output, as well as heat production & distribution to each part of the engine.

►    The integration of the vehicle & engine thermal management into the engine-cooling system significantly improves engine performance, there limitations to the overall benefits that can be achieved with a simplistic & passive engine-cooling system. The engine-cooling system can be improved significantly with the inclusion of advanced design & operating features, allowing the engine-cooling system to operate efficiently & effectively, indirectly improving fuel economy & lowering emission output.

►    Precision Cooling System

►    The precision cooling system is an engine cooling concept that is embodied in both the coolant gallery & the operating design of the system.

►    In a precision cooled system, thermally critical areas, such as the exhaust valve bridge are targeted with high coolant flow speeds to promote heat transfer without step temperature gradients or high heat flux, effectively lowering temperatures around these regions.

►    This is achieved by reducing the cross sectional area of the coolant passage in these regions to attain high flow speed without high bulk flow rate.

►    The key design point of a precision cooling system involves the sizing of the coolant gallery & matching of the coolant pump to ensure that the heat removal rate of the system can satisfy the limiting constraints on the operating  temperature in vulnerable regions at low speed, WOT conditions.

►    The coolant flow speed in this region can vary considerably with engine speed, from less than 1m/s at idle conditions to a high of 5m/s at maximum power conditions. Thus, the design of the gallery & the cooling system as a whole must complement each other to maximize the potential benefits.

►    The use of linear coolant galleries in the cylinder head pushes the coolant flow speed from a maximum of 1.4m/s in a standard gallery design to more than 4m/s in a precision cooled head, greatly promoting heat transfer & thus reducing the metal temperature in the cylinder head by up to 60oc

►    Split Cooling System or Dual Circuit Cooling System

►    In a split cooling system, the head & the block of the engine are cooled by independent circuits, thereby allowing flexibility in regulating the temperature of each section of the engine.

►    A split cooling system gives a unique advantage to an engine as it allows each sections of the engine to operate at its optimum temperature set points, maximizing the overall effect of the engine performance.

►    Each circuit would operate with a different coolant temperature set point or flow rate to create the desired temperature distribution in the engine.

►    The desired thermal operating conditions for the engine is to have the running cooler while having the block running warmer relative to the standard conditions.

►    By running the head cooler, volumetric efficiency improves, increasing the mass of trapped air, albeit at lower temperature.

►    The increase in trapped air mass at a lower temperature allows a more rapid & complete combustion, reducing CO, HC, & NOx formations, while increasing the output power.

►    Higher block temperature would reduce frictional losses, contributing to fuel efficiency improvement & indirectly lower the peak in cylinder pressure & temperature, which has a strong association with NOx formation.

►    Controlled Engine Cooling

►    The convectional engine cooling system still used on modern engines is a passive system designed for simplicity & cost effectiveness. The controllability of the engine cooling system is a desirable feature, which mainly relate to deficiencies of the current system.

►    This problem is more prominent for light duty vehicles, as these vehicles are operated mostly for city driving, at part load operation, which uses a small proportion of the available engine power, incurring high losses in the cooling system.

►    with any control system, the element in the system includes sensors, actuators, & controller, with electrical & electronic modules favored to replace their mechanical counterparts, due to the ease of implementation of a controllable system.

►    The advantages of a controllable engine cooling system is clear, with its ability to compensate for the engine operating conditions, minimizing losses,  adjusting cooling supply to match demand, & thus reduce auxiliary power requirement without sacrificing engine protection.

►    The ability of the system is highlighted by the fact that coolant temperature can be reduced by 10oC to 110oC in 2s. this allows the system to run close to the operating limits of the engine & reduce warm up time by up to 200s, the ability to regulate coolant or metal temperature to a narrow range is also beneficial to reduce metal fatigue arising from thermal cycling load, thus prolonging component life.

►    Problem & Objectives

►    We tried to investigate the best option to run the SI engine on gasoline in vast varying temperature range and simultaneously to maintain the emission norms.

►    There are many strategies for improving fuel economy and reducing exhaust emission HC & CO. The experimental study is carried out in the laboratory on a three cylinder, four strokes, petrol, water cooled engine test rig connected to eddy current type dynamometer.

►    The objective of this work was to examine important engine performance parameter, like brake specific fuel consumption (BSFC), brake power (BP) and also exhaust emissions on varying engine temperatures.

►    The investigation and testing was based on the  temperature of engine systems under different operating conditions.

►    Engine Tests Observations

►    The whole study is mainly based on the Engine Temperature Effects on various important operating parameters.

►    The values of engine performance parameter were directly obtained by “Engine Soft” software. A test matrix was created to record the engine performance parameter but main focal point was on specific fuel consumption and brake power of the engine at different engine speed 1500, 2000, 2500, 3000 rpm with the engine load of 6,9,12,14 kg (part load) at manually controlled engine temperature 50,60,70,80,90 oC and subsequent effect on emission level. (CO, CO2, HC, Nox)

►    The engine connected to the test rig was tested under three pre- decided conditions; initially it was tested on standard engine setting with automotive gasoline for part load conditions at different engine speed and temperatures then it was tested again with the improved engine settings for better running condition with gasoline.

►    Looking into these sets of operating parameters and their behaviors a few selected sets are being further analyzed particularly to know the effect of temperature on other operating parameters as shown in the graphical representations.

►     The same is being taken in to consideration for the final discussion and subsequently to conclude the experimental analysis.

►    Conclusions

1.     Brake Specific fuel consumption falls with the increase in engine temperature up to 800C. Average fall in specific fuel consumption is 10-15% at different engine speed and at lower engine load, up to 5% at increased load on the engine.

2.     It is important to mention that the fall in SFC at higher load is significant on temperatures at 70-800C. This reduction is in the range of 10-20% from the maximum value. At engine temperature above 700C it is observed that the reduction in SFC from its maximum value is in the range 5-15%. This is the most important information as it suggests the importance of engine temperature in the light of engine performance.

3.     In summary, the high temperature  has negative effects on engine performance, fuel economy and engine structural elements.

4.     When engine runs with gasoline at the same operating conditions it has positive effects on obnoxious exhaust emissions such as CO and HC and adversely affecting NOx at such high temperatures.

5.      It has been also found that at 12kg dynamometer load, the behavior of SFC and B.P. curves are almost similar for all temperatures

6.     In the case of using LPG in SI engines, the burning rate of fuel is increased, and thus, the combustion duration is decreased. As a consequence of this, the cylinder pressures and temperatures predicted for LPG are higher than those obtained for gasoline. This may cause some damages on engine structural elements.

7.     LPG reduces the engine volumetric efficiency and, thus, engine effective power. Furthermore, the decrease in volumetric efficiency also reduces the engine effective efficiency and consequently increases specific fuel consumption.

8.     A mole fraction of CO and NO with LPG decreases in the exhaust gases.As is known, LPG has a high octane number. Thus, it may lead to operating with higher compression ratios, and consequently, the engine efficiency and fuel economy would be better than those determined here.

►    FUTURE SCOPE OF WORK

►    There are many more areas in which the investigation of temperature effect on IC engines operating parameters can also be evolved by utilizing better instrumentation and laboratory facilities. One of the major fields of investigation of temperature effects on engines are the modification and testing of engine cooling system working and design. Looking into different climatic region in our country a typical cooling system is essentially required for automotives to perform well on the fuel economy front. Especially the heavy duty transportation vehicle running on highways are use to face the problem of load and temperature particularly during summer season and therefore they needed emergent relief.

►    To get better fuel economy with controlled emissions, the investigation of total heat balance is required to be managed and the effect of temperature on fuel administrating system and combustion is also required to be examined for better performance of the automotive engines. With controlled operating temperature running condition of automotive engines may also prolong the life of the engine parts and particularly the engine oil changing period.

►    Combustion analysis relating to different compression/equivalence ratio for gaseous fuels at various temperatures can also be performed with better instrumentation in the laboratory. This may be helpful to optimize the fuel consumption with emission balance particularly for tropical country like India.  

►    The better balanced management of engine heat and atmospheric temperature is still required to run the automotives engine perfectly with high fuel economy for sustainable environmental conditions in the interest of the users and our country.