Gautam T. Kalghatgi

• B.Tech (I.I.T. Bombay, 1972), Ph.D. (Bristol,1975)
• Retired

90% of current primary energy use in India is from fossil fuels, with coal being dominant; the demand for energy is expected to at least double by 2050. In the short to medium term, India is focusing on ensuring that it has affordable energy to enable economic development and poverty reduction rather than on climate change concerns. For instance, i...

Global climate change and local air quality concerns due to transport activities have led to several governmental interventions to accelerate the transition of internal combustion engine vehicles (ICEVs) powered transport sector to alternative powertrains such as battery electric vehicles (BEVs). In today’s world, every county is aiming for sustain...

The dominant narrative in the affluent west is that climate change poses an “existential threat” and very rapid cuts in greenhouse gas (GHG) emissions and hence fossil fuel use are needed to avoid it. Simultaneously oil, gas, coal, aviation, steel and cement industries and livestock farming have to be largely shut down to eliminate GHG. This review...

Battery-electric vehicles (BEV) have emerged as a favoured technology solution to mitigate transport greenhouse gas (GHG) emissions in many non-Annex 1 countries, including India. GHG mitigation potentials of electric 4-wheelers in India depend critically on when and where they are charged: 40% reduction in the north-eastern states and more than 15...

Gasoline Compression Ignition (GCI) engines offer the prospect of diesel-like high efficiency while making the control of particulates and NOx emissions much easier. In the GCI concept, gasoline-like fuels which are much more difficult to autoignite compared to diesel fuels, are used with injection strategies which enable partially premixed combust...

The global vehicle population is increasing, resulting in increased fuel demand. Diesel engines are highly efficient, but there are environmental concerns about their emissions. However, diesel engines are the main prime movers for heavy-duty transport globally. Global demand for diesel and jet fuel is expected to increase faster than gasoline, lea...

Global transport is almost entirely powered by internal combustion engines (ICEs) and petroleum-derived liquid fuels. Currently, there are many efforts to move transport away from this energy system to reduce its carbon footprint. In addition, tailpipe emissions from ICEs have to meet increasingly stringent standards. However, all the alternatives,...

This book focuses on clean transport and mobility essential to the modern world. It discusses internal combustion engines (ICEs) and alternatives like battery electric vehicles (BEVs) which are growing fast. Alternatives to ICEs start from a very low base and face formidable environmental, material availability, and economic challenges to unlimited...

Current energy policy in most western countries is based on the assumption that there is a “climate emergency” which requires that greenhouse gas (GHG) levels need to be rapidly brought down to zero. However, the scale of the energy transition needed does not seem to be sufficiently appreciated or if it is, the detailed and urgent plans needed to m...

There is widespread belief that climate change poses an "existential threat" and drastic and rapid cuts in greenhouse gas (GHG) emissions and hence fossil fuel use are needed to cope with it. However, empirical evidence shows that humanity has coped well with the past rise in temperature caused substantially by human activities. Moreover, fossil fu...

Currently 99.8 % of global transport is powered by internal combustion engines (ICEs) and 95% of transport energy comes from liquid fuels made from petroleum. Many alternatives including battery electric vehicles (BEVs) and other fuels like biofuels and hydrogen are being considered. However, all these alternatives start from a very low base and fa...

The global demand for transport energy is large, growing, and primarily met by petroleum-derived liquid fuels powering internal combustion engines (ICEs). Moreover, the demand for jet fuel and diesel is projected to grow faster than the demand for gasoline in the future, and is likely to result in low-octane gasoline components becoming more readil...

Different octane specification methods were evaluated under rising ethanol blending volumes by adopting a refinery economics model to represent a region in the U.S. It was demonstrated that the traditional octane specification methods, such as the Anti-knock Index (AKI) used in the U.S., or the Research Octane Number (RON) and Motor Octane Number (...

Transport is almost entirely powered by internal combustion engines (ICEs) burning petroleum-derived liquid fuels and the global demand for transport energy is large and is increasing. Available battery capacity will have to increase by several hundred fold for even light duty vehicles (LDVs), which account for less than half of the global transpor...

Ethanol is one of the most desirable fuels for spark-ignition engines. It offers high-octane quality and a latent heat of vaporization that is four times greater than gasoline on a stoichiometric basis. Anhydrous ethanol can also readily be blended into oil-based fuels, thereby enabling improved engine efficiency and reduced greenhouse gas (GHG) em...

Gasoline anti-knock quality, defined by the research and motor octane numbers (RON and MON), is important for increasing spark ignition (SI) engine efficiency. Gasoline knock resistance can be increased using a number of blending components. For over two decades, ethanol has become a popular anti-knock blending agent with gasoline fuels due to its...

Petroleum-derived gasoline is currently the most widely used fuel for transportation propulsion. The design and operation of gasoline fuels is governed by specific physical and chemical kinetic fuel properties. These must be thoroughly understood in order to improve sustainable gasoline fuel technologies in the face of economical, technological, an...

Higher octane gasoline will be an important factor in enabling future spark-ignition engines to meet increasingly stringent fuel economy and CO2 emissions requirements. The most effective method to raise the octane ‘floor’ of regular grade gasoline is through the use high octane blend components, such as methanol and ethanol. However, this is often...

Knock is an abnormal and stochastic combustion phenomenon which limits the efficiency of spark ignition engines. It occurs because of autoignition initiated locally in hot spots in the fuel/air mixture ahead of the advancing flame front. The onset of knock is governed by chemical kinetics and is determined by the pressure and temperature history of...

Advanced engine technologies will play a central role in achieving future greenhouse gas (GHG) emissions targets for light-duty vehicles. However, these technologies will place greater emphasis on optimizing the engine and fuel as a synergistic system, since many technologies will require higher octane gasolines to realize their full social and env...

Higher fuel anti-knock quality will be required as spark ignition engines are designed for higher efficiency in the future. This paper introduces a new high-octane gasoline blending component made from low value mixed butenes using a new process. The component named SuperButol(TM) is mainly a mixture of butanol isomers (-93%) with small amounts of...

The worldwide demand for transport fuels will increase significantly but will still be met substantially (a share of around 90%) from petroleum-based fuels. This increase in demand will be significantly skewed towards commercial vehicles and hence towards diesel and jet fuels, leading to a probable surplus of lighter low-octane fuels. Current diese...

Most studies on knock ignore the stochastic nature of knock and focus on the onset of knock which is determined by chemical kinetics. This paper focuses on knock intensity (KI) which is determined by the evolution of the pressure wave following knock onset in a hot spot and highlights the stochastic processes involved. KI is defined in this study a...

This paper reviews the fundamental requirements of liquid hydrocarbon fuels for spark ignition engines, namely that the fuel should vaporise satisfactorily and burn in a controlled manner. The phenomenon of knock and the development of the octane scale are discussed. The variation in the pressure–time histories for different engines is discussed, t...

Higher fuel anti-knock quality will be required as spark ignition engines are designed for higher efficiency in the future. This paper introduces a new high-octane gasoline blending component made from low value mixed butenes using a new process. The component named SuperButol™ is mainly a mixture of butanol isomers (∼93%) with small amounts of dii...

A methodology for estimating the octane index (OI), the research octane number (RON) and the motor octane number (MON) using ignition delay times from a constant volume combustion chamber with liquid fuel injection is proposed by adopting an ignition quality tester. A baseline data of ignition delay times were determined using an ignition quality t...

Gasoline compression ignition (GCI) engines could be more efficient than most advanced SI engines while running on lower octane fuel. GCI engines may utilize a mixture of different fuels and fuel components such as gasoline and diesel or diesel and naphtha. The risks and hazards associated with such mixtures must be studied to ensure safe fuel stor...

As demand evolves, as specifications change, and as new fuel opportunities arise, what are the implications for refiners up to mid-century?

As demand evolves, as specifications change, and as new fuel opportunities arise, what are the implications for refiners up to mid-century?

Predicting octane numbers (ON) of gasoline surrogate mixtures is of significant importance to the optimization and development of internal combustion (IC) engines. Most ON predictive tools utilize blending rules wherein measured octane numbers are fitted using linear or non-linear mixture fractions on a volumetric or molar basis. In this work, the...

A detailed chemistry and pollutant formation model combined with an advanced combustion simulation tool DI-SRM (direct injection stochastic reactor model) and time based mixing model are used to simulate the in-cylinder physico-chemical processes such as compression, heat transfer, charge stratification/mixing and gas phase chemistry in a single cy...

Transport energy comes primarily from liquid fuels from petroleum and will continue to do so. The demand will grow, mainly in developing countries and will be heavily skewed towards diesel and jet fuel rather than gasoline. There will be sufficient supply of oil to meet this growing demand over the next few decades. Future fuel properties will also...

The autoignition resistance of a practical gasoline is best characterized by the Octane Index, OI, defined as RON-KS, where RON and MON are respectively, Research and Motor Octane Numbers, S is the sensitivity (RON-MON) and K is a constant depending on the pressure and temperature history of the fuel/air mixture in an engine. Experiments in knockin...

Changes in engine technology, driven by the need to increase the efficiency of the SI engine and reduce NOx and soot from diesel engines, and in transport energy demand will have a profound effect on the properties, specifications and production of future fuels. The expected increase in global demand for transport energy is significantly skewed tow...

The demand for transport energy is increasing, but this increase is heavily skewed toward heavier fuels such as diesel and jet fuel while the demand for gasoline might decrease. As spark-ignition engines develop to become more efficient, abnormal combustion such as knock and preignition will become more likely. High antiknock quality fuels, those w...

SAE 2014-01-2609 As SI engines strive for higher efficiency they are more likely to encounter knock and fuel anti-knock quality, which is currently measured by RON and MON, becomes more important. However, the RON and MON scales are based on primary reference fuels (PRF) – mixtures of iso-octane and n-heptane – whose autoignition chemistry is signi...

SAE Paper 2014-01-1301 In the context of stringent future emission standards as well as the need to reduce emissions of CO2 on a global scale, the cost of manufacturing engines is increasing. Naphtha has been shown to have beneficial properties for its use as a fuel in the transportation sector. Well to tank CO2 emissions from the production of Nap...

Fuel is required for an engine to produce work. Reciprocating internal combustion engines are classified by the manner by which this fuel is ignited: spark ignition (SI) or compression ignition (CI). The specific effects of changing a given fuel property depend on many detailed parameters of the engine and combustion strategy in which the fuel is u...

Recent research [21] has shown that the compression ignition concept where very low cetane fuels (RON between 70 and 85) are run in compression ignition (CI) mode has several advantages. The engine will be at least as efficient and clean as the current diesel engines but will have a less complicated after-treatment system. The optimum fuel will be...

If fuels that are more resistant to auto-ignition are injected near TDC in compression ignition engines, they ignite much later than diesel fuel and combustion occurs when the fuel and air have had more chance to mix. This helps to reduce NOX and smoke emissions at much lower injection pressures compared to a diesel fuel. However, PPCI (Partially P...

SAE Paper 2013-01-0267 Demand for transport energy is growing but this growth is skewed heavily toward commercial transport, such as, heavy road, aviation, marine and rail which uses heavier fuels like diesel and kerosene. This is likely to lead to an abundance and easy availability of lighter fractions like naphtha, which is the product of the ini...

If fuels that are more resistant to autoignition are injected near top dead centre in compression ignition engines, they ignite much later than diesel fuel does, and combustion occurs when the fuel and air have had more chance to mix. This helps to reduce nitrogen oxide and smoke emissions. Moreover, this can be achieved at much lower injection pre...

Earlier studies of pre-ignitions at hot surfaces are first reviewed. The concept of a critical radius of a hot pocket of gas, closely related to the laminar flame thickness, that is necessary to initiate a propagating flame, has been used successfully to predict relative tendencies of different fuel–air mixtures to pre-ignite. As the mixture is com...

Fuels that are more resistant to autoignition allow more time for mixing before combustion occurs and help to reduce nitrogen oxides (NOx) and smoke in a diesel engine. However, hydrocarbon (HC) and carbon monoxide (CO) emissions are high at low loads because combustion is more likely to take place in lean mixture packets with better mixing caused...

In this paper blends of diesel and gasoline (dieseline) fuelled Partially Premixed Compression Ignition (PPCI) combustion and the comparison to conventional diesel combustion is investigated. The tests are carried out using a light duty four cylinder Euro IV diesel engine. The engine condition is maintained at 1800 rpm, 52 Nm (equivalent IMEP aroun...

SAE Paper 2012-01-0677 More stringent emissions standards along with higher fuel economy demands have obliged auto makers to develop technical solutions that exploit synergistic features from gasoline and diesel engines. To minimize NOx and soot trade-off, diesel powertrain has been developed to adopt increasingly complex and expensive technology s...

SAE Paper No. 2012-01-1634 Extensive tests have been carried out in a single-cylinder Direct Injection Spark Ignition (DISI) engine using up to fifteen different fuels at inlet pressure of up to 3.4 bar abs. to study fuel effects as well as inlet pressure effects on knock. In addition fuel effects on particulate emissions at part-throttle were meas...

A single-cylinder diesel engine has been run on gasolines of different octane numbers and on model fuels, mixtures of iso-octane, n-heptane and toluene, at different operating conditions. The autoignition quality of the fuel is best described by an Octane Index, OI=(1−K)·RON+K·MON for fuels in the gasoline autoignition range where RON and MON are,...

Simple surrogate fuels are needed to model practical fuels, which are complex mixtures of hydrocarbons. The surrogate fuel should match the combustion and emissions behaviour of the target fuel as much as possible. This paper presents experimental results using a wide range of fuels in both the gasoline and diesel auto-ignition range, but of differ...

Conventional diesel fuelled Partially-Premixed Compression Ignition (PPCI) engines have been investigated by many researchers previously. However, the ease of ignition and difficulty of vaporization of diesel fuel make it imperfect for PPCI combustion. In this study, Dieseline (blending of diesel and gasoline) was looked into as the Partially-Premi...

Premixed Charge Compression Ignition (PCCI) is a combustion concept that holds the promise of combining emission levels of a spark-ignition engine with the efficiency of a compression-ignition engine. In a short term scenario, PCCI would be used in the lower load operating range only, combined with conventional diesel combustion at higher loads. Th...

Regulations on emissions from diesel and gasoline fuelled engines are becoming more stringent in all parts of the world. Hence there is a great deal of interest in developing advanced combustion systems that offer the efficiency of a diesel engine, but with low PM and NOx. One promising approach is that of Partially-Premixed Compression Ignition (P...

In diesel engines, fuels that are more resistant to autoignition allow more time for mixing before combustion occurs and help reduce NOx and smoke. The fuel is injected near but before TDC in order to ensure in-cycle control over combustion phasing through injection timing and must not be fully premixed with air as in HCCI combustion. The present w...

Much of the technology in advanced diesel engines, such as high injection pressures, is aimed at overcoming the short ignition delay of conventional diesel fuels to promote premixed combustion in order to reduce NOx and smoke. Previous work in a 2 litre single cylinder diesel engine with a compression ratio of 14 has demonstrated that gasoline fuel...

In this paper, new experimentally determined octane numbers (RON and MON) of blends of a tri-component surrogate consisting of toluene, n-heptane, i-octane (called toluene reference fuel TRF) arranged in an augmented simplex design are used to derive a simple response surface model for the octane number of any arbitrary TRF mixture. The model is se...

This research describes the potential to adopt detailed chemical kinetics for practical and potential future fuels using tri-component surrogate mixtures capable of simulating fuel octane "sensitivity". Since the combustion characteristics of modern fuels are routinely measured using the RON and MON of the fuel, a methodology to generate detailed c...

Previous work has shown that it may be advantageous to use gasoline type fuels with long ignition delays compared to today's diesel fuels in compression ignition engines. In the present work we investigate if high volatility is also needed along with low cetane (high octane) to get more premixed combustion leading to low NO and smoke. A single-cyl...

ASME Paper # ICES2009-76034 Much of the technology in advanced diesel engines, such as high injection pressures, is aimed at overcoming the short ignition delay of conventional diesel fuels to promote premixed combustion in order to reduce NOx and smoke. Previous work in a 2 litre single cylinder diesel engine with a compression ratio of 14 has dem...

The functional relationship of autoignition delay time with temperature and pressure is employed to derive the propagation velocities of autoignitive reaction fronts for particular reactivity gradients, once autoignition has been initiated. In the present study of a variety of premixtures, with different functional relationships, such gradients com...

Previous work has showed that it may be advantageous to use fuels of lower cetane numbers compared to today’s diesel fuels in compression ignition engines. The benefits come from the longer ignition delays that these fuels have. There is more time available for the fuel and air to mix before combustion starts which is favourable for achieving low e...

The paper presents experimental studies of the liftoff and blowout stability parameters of pure hydrogen, hydrogen/propane and hydrogen/methane jet flames using a 2mm burner. Carbon dioxide and Argon gas were also used in the study for the comparison with hydrocarbon fuel. Comparisons of the stability of H2/C3H8, H2/CH4 and H2/CO2 flames showed tha...

Combustion in HCCI engines is a controlled auto-ignition of well-mixed fuel, air and residual gas. The thermal conditions of the combustion chamber are governed by chemical kinetics strongly coupled with heat transfer from the hot gas to the walls. The heat losses have a critical effect on HCCI ignition timing and burning rate, so it is essential t...

Extremely high knock intensities are observed occasionally in turbo charged spark ignition (SI) engines. Such events have been informally described as "Super knock" and are often associated with pre-ignition. Knock is initiated by auto ignition at one or more "hot spots". The mode of propagation of the resulting pressure wave depends on the propaga...

A semidetailed mechanism (137 species and 633 reactions) and new experiments in a homogeneous charge compression ignition (HCCI) engine on the autoignition of toluene reference fuels are presented. Skeletal mechanisms for isooctane and n-heptane were added to a detailed toluene submechanism. The model shows generally good agreement with ignition de...

Ignition times were determined in high-pressure shock-tube experiments for various stoichiometric mixtures of two multicomponent model fuels in air for the validation of ignition delay simulations based on chemical kinetic models. The fuel blends were n-heptane (18%)/isooctane (62%)/ethanol (20%) by liquid volume (14.5%/44.5%/41% by mole fraction)...

In the study the lift-off, blow-out and blow-off stability limits of hydrogen/propane flames and hydrogen/carbon dioxide flames were tested in three different mixing arrangements. The first was to premix hydrogen with carbon dioxide or propane to form a jet flame. The second was to add the gas as an annular jet around the hydrogen flame. The third...

A detailed chemical kinetic model for the autoignition of toluene reference fuels (TRF) is presented. The toluene submechanism added to the Lawrence Livermore Primary Reference Fuel (PRF) mechanism was developed using recent shock tube autoignition delay time data under conditions relevant to HCCI combustion. For two-component fuels the model was v...

The ignition delay times of mixtures containing 35% n-heptane and 65% toluene by liquid volume at room temperature (i.e., 28% n-heptane/72% toluene by mole fraction) were determined in a high-pressure shock tube in the temperature range 620⩽T⩽1180 K at pressures of about 10, 30, and 50 bar and equivalence ratios, ϕ, of 0.3 and 1.0. The equationτ/μs...

SAE 2007-01-0006 A Swedish MK1 diesel fuel and a European gasoline of ~95 RON have been compared in a single cylinder CI engine operating at 1200 RPM with an intake pressure of 2 bar abs., intake temperature of 40°C and 25% stoichiometric EGR at different fuelling rates and using different injection strategies. For the same operating conditions, ga...

SAE Paper 2006-01-3385 Oxides of nitrogen (NOx) and smoke can be simultaneously reduced in compression ignition engines by getting combustion to occur at low temperatures and by delaying the heat release till after the fuel and air have been sufficiently mixed. One of the ways to obtain such combustion in modern engines using common-rail direct inj...

Combustion phasing is characterized by CA50, the crank angle position where 50 per cent of the total heat release occurs. CA50 = (a + b) [OI - OI0] where OI is the octane index defining the fuel auto-ignition quality given by OI = (1 - K) RON + K MON = RON - KS and S is the sensitivity of the fuel, (RON - MON). K, (a + b), and OI0, which is the req...

In this work the influence of NO on combustion phasing has been studied experimentally in a single-cylinder HCCI engine. An isooctane/n-heptane blend (PRF), a toluene/n-heptane mixture (TRF) and a full boiling range gasoline were tested at two different operating conditions with NO concentrations ranging from 4 up to 476 ppm in the fresh intake air...

SAE 2005-01-2127 In Homogeneous Charge Compression Ignition (HCCI) engines heat release occurs by auto-ignition and hence the fuel auto-ignition quality is very important. The auto-ignition quality of Diesel fuels is conventionally described by the cetane number. Conventional Diesel fuels are involatile compared to gasoline fuels and mixture prepar...

SAE 2005-01-2106 Predictive simulation models are needed in order to exploit the full benefits of 1-D engine simulation. Simulation model alterations such as cam phasing affect the gas composition and gas state in the cylinders and have an effect on the combustion. Modelling of these effects is particularly important when the engine is knock limite...

SAE 2005-01-0244 The anti-knock or octane quality of a fuel depends on the fuel composition as well as on the engine design and operating conditions. The true octane quality of practical fuels is defined by the Octane Index, OI = (1-K)RON + KMON where K is a constant for a given operating condition and depends only on the pressure and temperature v...