Engine Block Research Articles

An investigation on the friction losses between cylinder liner and piston rings

Historically, the engine crankcase has been made of gray cast iron due to that material's' high machinability, damping ability, thermal conductivity, and sensible cost. Despite these advantages and the long-term use of gray cast iron, the vehicle manufacturers predominately use cast aluminum as material of choice for the engine block due to aluminum’s density being almost a third of that of gray cast iron, and the aluminum engines have the same durability as gray cast iron while weighing considerably less. However, due to the low wear resistance of aluminum, efforts are needed to improve internal working surfaces such as the use of cast iron cylinder liners or the application of a protective coat is applied to the aluminum surface to increase its resistance. The purpose of this study is to examine which ring materials have the lowest friction with the Twin Wire Arc (TWA) aluminum cylinder liner. An Ansys simulation model accomplishes the experimental work. The steel ring material obviously had the lowest friction with twin wire arc spray aluminum cylinder liner as opposite to the cast iron material which was the worst.

Heuristic Approach for a Combined Transfer Line Balancing and Buffer Allocation Problem Considering Uncertain Demand

In this paper, we refer to a real case study of an industrial partner recently committed to its project on the design of a multi-unit and multi-product manufacturing system. Although the considered problem refers to an actual complex manufacturing system, it can be theoretically classified as a union of two key problems that need to be solved during the transfer line design stage: the transfer line balancing problem (TLBP) and the buffer allocation problem (BAP). As two closely related problems, TLBP and BAP usually have similar optimizing directions and share the same purpose: finding a balance between the performance of the transfer line system as well as minimizing investment costs. These problems are usually solved sequentially, but this leads to solutions close to a local optimum in the solution space and not to the global optimum of the overall problem. This paper presents a multi-objective optimization for concurrently solving transfer line balancing and buffer allocation problems. The new approach is based on a combination of evolutionary and heuristic-based algorithms and takes into account the uncertainty of market demand. To validate the proposed approach, an industrial case study in a multi-unit manufacturing system producing multiple products (four engine blocks) is discussed.

Twisting Linear to Orbital Angular Momentum in an Ultrasonic Motor.

An ultrasonic motor built with a contactless meta engine block (MEB) is designed and experimentally demonstrated for twisting the linear momentum of sound emanating from a Helmholtz resonator-based metasurface into orbital angular momentum (OAM). The MEB is capable of hosting highly efficient excitations of eigenmodes carrying desired OAM whose Bessel acoustic intensity patterns are enhanced by over ten times compared to the incident wave. Thanks to this efficiency, bidirectional ultrasonic OAM is capable of driving loads at speeds up to 1000rpm at 4 W and remarkable sound radiation torque levels. Moreover, the possibility of using arbitrarily shaped MEBs is also demonstrated by engineering its physical boundary condition based on an analytically derived criterion to guarantee the high twisting efficiency of man-made OAM. The results show how noninvasive driving of an ultrasonic motor can be made possible through appropriately designed momentum twisting, which opens the door to a new class of integrated mechanical devices solely powered by sound.

Cold Spray of Nickel-Based Alloy Coating on Cast Iron for Restoration and Surface Enhancement

Cold spray is an emerging additive manufacturing process that allows particles to be coated onto the surface of a base material without melting. It is suitable to repair components made from temperature-sensitive materials, such as grey cast iron, which cannot be easily restored using conventional methods like welding or thermal spray. In this study, the nickel-based alloy Inconel 625 was successfully coated onto a grey cast iron (GJL250) using a cold spray process, and extensive experiments were carried out to study the effects of diffusion between the coating and the substrate after heat treatment at 400, 600, 850 and 1050 °C for 3 and 6 hours durations. The coatings in all conditions were dense (0.25% to 3%) and had defect-free interfaces. Under heat treatment, the diffusion layer increased in thickness with increasing temperature and duration due to atomic diffusion. The Inconel 625 coating is also shown to be effective against oxide growth as compared to grey cast iron. The hardness of the coatings is also stable at high temperatures. The heat-treated coatings at 600 °C achieved a peak hardness of around 500 HV, which is 30% and 60% higher than the as-sprayed coating and grey cast iron substrate, respectively, because of the possible formation of recrystallized nanostructured grains and strengthening precipitates. These findings demonstrate the potential application of using cold spray on nickel-based alloy coatings for restoration and surface enhancement of grey cast iron components, such as engine blocks and pump housings.

A study on vibration prediction of diesel engine based on virtual material modeling method of joint surfaces

The vibration prediction model of diesel engine is generally established by finite element method (FEM). In FEM, the components are firstly represented by mesh models, which will be connected to develop a combined model through joint surfaces. The processing method of joint surfaces is key to the accuracy of the combined model, for joint surfaces play an important role in transmitting force and vibration. For this purpose, an equivalent model of transversely isotropic virtual material is proposed to connect the mesh models of the components in this paper. In this model, the different connection characteristics of both normal and tangential are taken into consideration. In addition, the calculation models of the virtual material layer parameters, such as elastic modulus, shear modulus, Poisson’s ratio, thickness, density, and damping coefficient, are established in theory. At the same time, the modal test is introduced to acquire the natural frequency and damping ratio for identifying the unknown parameters of the virtual material layer, by using the BP neural network algorithm. After that, the complete finite element model of a diesel engine assembly can be established, and the vibration prediction is made in time domain, where cylinder gas pressures, piston slap forces, main bearing forces, and valve train forces are taken into consideration comprehensively. Furthermore, the experiment of the engine vibration response is carried out as well. The vibration acceleration level of engine feet and the vibration severity of engine block are adopted to evaluate the structure vibration response of the diesel engine. The results show that there is a good consistency between the prediction results and the experiment results in frequency domain. The consistency of the vibration acceleration level in 1/3 octave is up to 8 kHz, and that of the vibration severity is up to 1 kHz. And the results verify the accuracy of the vibration prediction model of the diesel engine, which is based on transversely isotropic virtual material modeling method of joint surfaces.

Spinal block characteristics of intrathecal 1% 2chloroprocaine following addition of dexmedetomidine versus fentanyl in lower abdominal surgery: A prospective randomised controlled double blinded study

The use of spinal anaesthesia for day care lower abdominal surgeries is limited due to its characteristics like delayed ambulation, urinary retention etc. The ultrashort acting 1% 2chloroprocaine (2CP) shows the properties of ideal local anaesthetic for short duration surgeries. The aim of this study was to compare the efficacy of two different adjuvants (fentanyl or dexmedetomidine) with intrathecal2CP for spinal block characteristics.A prospective randomised double blinded study was conducted on 126 patients scheduled for short duration lower abdominal surgeries under spinal anaesthesia. They were randomised into 3 groups. Group C received 40µg of 1% 2CP while group F received 2CP + 25µg fentanyl; and group D received 2 CP + 10µgdexmedetomidine. Tactile and engine bar qualities, prerequisite of post usable absence of pain, haemodynamics and sedation score were evaluated. The segment information, length of medical procedure, beginning of tangible square, an ideal opportunity to arrive at top tactile level were practically identical in every one of the three groups(P>0.05). Span of tactile & engine block & postoperative absence of pain was essentially delayed in bunch D versus bunch F & gathering C(P<0.001). Intrathecal addition of dexmedetomidine (10µg) & fentanyl (25µg) to 1%2CP brought about an essentially delayed tangible & engine bar with postoperative absence of pain. However, dexmedetomidine was viewed as a preferable adjuvant over fentanyl as far as drawn out length of absence of pain with insignificant secondary effects.

Wear Study of Cubic Boron Nitride (cBN) Cutting Tool for Machining of Compacted Graphite Iron (CGI) with Different Metalworking Fluids

Due to its desirable mechanical properties, compacted graphite iron (CGI) has been used to replace conventional gray cast iron (CI) in various applications, such as automotive engine blocks and cylinder heads. However, the poor machinability of CGI can lead to excessive tool wear and consequently high manufacturing costs. Various strategies have been developed to improve the machinability of CGI, including optimizing machining parameters and the development of novel metalworking fluids. In this study, machining of CGI was conducted using cubic boron nitride (cBN) tools under different cutting speeds, with both soluble and full-synthetic water-based metalworking fluids at different levels of sulfur addition and water dilution. The effects of the metalworking fluids on the tool wear behavior were examined. Results showed that at 200 m/min cutting speed, the soluble metalworking fluid at 4% dilution and 0.3% sulfur compound exhibited the best performance, with a cutting distance reaching 23.8 km. In contrast, the least effective soluble metalworking fluid at 9% dilution and 0.3% sulfur compound resulted in a 28.6% decrease in the cutting distance (17.0 km) compared to the best one. At a higher speed (300 m/min), the cutting distance for all metalworking fluids dropped to less than 6.0 km, with the full-synthetic metalworking fluid showing the shortest cutting distance of 4.8 km.

Structural efficiency of block for aviation piston heavy fuel engine

PurposeHigh reliability and high power-to-weight ratio are the technical difficulties in the development of aviation piston heavy fuel engines. This paper aims to provide a design evaluation method of the aero piston engine block, which can help R&D personnel quickly evaluate the performance of engine block, including effective bearing capacity and fatigue deformation, save a lot of experimental time and shorten the R&D cycle.Design/methodology/approachIn this paper, structural efficiency is used to evaluate the reliability and durability of the engine block. Structural efficiency is a new evaluation method that lists its corresponding connotation according to different objects. In this paper, the function of the engine block in the engine is explained in detail, and three quantifiable connotations of the structural efficiency of the engine block are put forward. In the subsequent calculation, the calculation is carried out according to the three indexes, and the calculation results are used as the indexes to evaluate the performance of the engine block.FindingsThe structural efficiency evaluation method proposed in this paper can quickly and effectively evaluate the performance of the block from many aspects. Under the same boundary conditions, the two design schemes are simulated and analyzed, and the durability test is carried out. The analysis and experimental results show that Scheme 2 has good performance, which verifies the feasibility of the evaluation method.Originality/valueThis paper provides a method for rapid evaluation of engine block performance.

Evolution of residual stress through the processing stages in manufacturing of bore-chilled sand-cast aluminum engine blocks with pressed-in iron liners

To minimize the carbon footprint of the transportation industry, manufacturers and engineers are continuously trying to improve the efficiency of the combustion engine. However, due to the presence of iron cylinder liners in the engine block, high tensile residual stresses are generated during the manufacturing process which leads to a large reduction of the alloy’s useable strength. Thus, the present study utilized neutron diffraction to study, for the first time, the evolution of residual stress of sand-cast aluminum engine blocks that have eliminated the iron cylinder liners from the casting process and mechanically inserted them after heat treatment and machining operations. Moreover, this study also examined the effects that cylinder bore chills have on the resulting residual stress profiles. The replacement of the iron liners shifted the stress mode from purely tension to purely compression until the bore chills were removed. Following the removal of the bore chills, the maximum tensile stress at the top of the cylinder bridge was ~ 70% lower than the engine’s predecessor which was produced with iron liners. Moreover, in the production-ready state (i.e., T7 heat treated and press-fit liners inserted), the stress mode maintains the partially compressive nature, thereby lowering the material’s susceptibility to crack growth and propagation.Graphical Abstract

Evolution analysis of process-induced residual stress during the manufacture of diesel engine block

Evolution analysis of process-induced residual stress during the manufacture of diesel engine block

Ventilation Analysis of Simplified Engine Nacelle for Pusher Aircraft

The paper contains the results of CFD analysis of flow inside the simplified engine nacelle, containing the engine in a pusher configuration. The authors have tested a set of solutions to increase an efficiency of the cooling system of this type of engine. Unfortunately, all the positive effects of the fact, that the aircraft engine appears in the wake of the propeller during taxiing and waiting for takeoff, are nonexistent in this type of configuration. An engine overheating is here a problem, because an airflow has to be pulled through the nacelle to cool down the engine block and radiators of cylinder heads. That design demands to analyze the cover shape of the nacelle, to properly use the main propeller pressure jump on the one hand, and rather adequate and complicated flow inside the nacelle to be modelled on the other. The aircraft CAD geometry has been simplified to allow for simple changes of the nacelle cover shape and easily introducing new inlets and outlets. The results prove, that the proper application of scoops gives even better result, than simply removing the cover and baffles from the engine. The exhaust scoops should be placed near the propeller plane in such pusher configuration, because the engine is not covered by the propeller wake.

Exploring Casting Defects of AA7075 Alloy in the Gravity Die Casting Simulation of an IC Engine Block

The present work aims to investigate the different casting defects that arose during the gravity die casting process of an IC engine block made of AA 7075 alloy and also highlights the feasible solutions to eradicate those defects. The minimization of the casting defects is a very crucial task in an IC engine block. Experimental studies which are generally performed to reduce the casting defects are proven to be strenuous, costly, and time-consuming. To counter this, a thermal simulation model is proposed in the present study to identify the effect of the pouring temperature, mould temperature, and the number of chillers on the various casting defects such as cold shuts, air entrapment, mould erosion, and microporosity. A detailed parametric study is conducted on the proposed model to evaluate the outcomes of important process variables on the resulting casting defects. The simulation results predict, at pouring temperature of 963 K, mould temperature of 293.15 K and with the use of 2 chillers defect-free IC engine blocks can be casted. The optimum result obtained by the proposed model is validated by conducting a confirmative test predicting an average error of 6.98%. The proposed model is effective enough in getting rid of the numerous casting defects which cannot be identified using the traditional methods; thus increasing productivity. This can be used as an economical time-saving substitute to the experimental methods during casting of various engine parts.

Modal Analysis of Passive Engine Mount Assembly using Finite Element Analysis

Engine mounts play a vital role in reduction of noise and vibration. For an internal combustion engine, there exist two basic dynamic disturbances: a) the firing pulse due to the combustion of fuel in the cylinder and b) the inertia force and torque caused by the rotating and reciprocating parts. The firing pulses will cause a torque to act on the engine block about an axis parallel to the crank. The inertial forces are both parallel to the piston axis and perpendicular to the crank and piston axes. This dissertation describes the finite element approach for modal and static structural analysis of the engine mount used on an inline four-cylinder petrol engine. A 3D model of the mount was created with the help of Solid-Edge V19 software and the same was analysed for natural frequencies and total deformation using Ansys Workbench software. Further, torsional stiffness of the mount was obtained using finite element analysis and validated using experimental testing. Viscoelastic behaviour of rubber has also been discussed with the help of a Generalized Maxwell model (GMM). GMM was chosen after reviewing all the commonly used models. Later, an in-depth analysis of transmissibility was carried out using finite element analysis approach and a 6-DOF Mathematical model approach. Random vibration analysis was carried out and the resulting RMS accelerations were compared with the ISO-2631 standard.

Internal Combustion Engines: Modeling Internal Temperature as a Function of Time

Just like any thermodynamic system, combustion engines must be cooled to eliminate friction due to heat. Without proper cooling, internal components, such as connecting rods, rod bearings, and pistons can be severely damaged due to thermal expansion, leading to severe damage to the engine block or outright catastrophic failure. Modern engines are cooled using coolant, which flows through internal passageways within the engine block to pull heat away from the system. The use of coolant and external components, such as a water pump, radiator, and thermostat allow an engine to efficiently warm to standard operating temperature and remain at said temperature. Using standard calculus and differential equations, the model for the idle coolant temperature increase inside of an engine block as it approaches a steady state can be obtained. For overall application purposes, this model includes an arbitrary number of inlets and exits for coolant to flow through. This model can also be applied to air cooled or electric systems, such as small engines or electrical motors which produce a quantifiable amount of heat.

Design and Implementation of Engine Oil Pressure Switch Indicator

An incorrect engine oil pressure gauge and an incorrect engine oil pressure sensor will provide false indications of low engine oil pressure or high engine oil pressure. Standard oil pressure sensors work by displaying a warning signal when the oil pressure falls outside of the set range. Two important components to the oil pressure sensor include the spring-loaded switch and a diaphragm. The spring-loaded switch is connected to the diaphragm that is exposed to the oil pressure. Pressure switch indicator can be diagnosed using DMM and inspect visually on the engine block. Good type of switch helps the ECU of Automobile engine to understand the oil pressure and actuate the moving parts or actuators accordingly.

Enhanced Thermoelectric Power Generation Using Buck –Boost Converter

Energy generated in the vehicles depend on the engine and the fuel intake. But usually two thirds of the fuel added to the vehicle, which is, car, trucks bus etc. gets wasted as heat. The energy wasted as heat from areas like engine block, radiator, exhaust pipe engine coolant side and so on. So, to recover the waste heat as usable electrical energy back to the vehicle, Thermoelectric Generator (TEG) can be effectively utilized and its output power could be enhanced by connecting with buck boost converter. Here TEG with coupled inductor is used which produces smooth output with less ripples. TEG is placed in the engine exhaust of the vehicle and the output is connected with buck boost with coupled inductor converter so as to enhance the output voltage. Simulation using Comsol of single stage TEG without Buckboost converter produces an output of 6V.Interestingly TEG with Hotside temperature of 500K and coldside temperature of 300K with 127 legs is connected with buck boost converter with coupled inductor produces the output of 12 V and 0.65 mA is obtained to drive PIR sensor. Moreover in this paper Modified Maximum power point tracker (MPPT) algorithm is proposed to further improve the energy harvesting.

Dynamic Modelling of Piston the Motion in Combustion Engines

The presented work discusses a methodology for analysis of noise emissions from a diesel engine. A numerical model of the piston motion, analyzing its lateral, reciprocating and rotation motion, has been presented in order to investigate the lateral motion of the piston skirt assembly and resulting vibrations induced as a result of these motions in the engine block. Various parameters of modal analysis were obtained using the mobility analysis. The presented methodology was validated by data obtained from a diesel engine test set up. The predicted results matched well with those of measured data, hence validating the presented scheme.

Determining the effect of the turbocharger in a heavy-duty diesel engine using energy, exergy, sustainability and economic analysis

The experiments of the 16-cylinder turbocharged heavy-duty diesel engine operating with two different turbochargers were conducted at a constant speed and variable load conditions. Energy, exergy, sustainability and thermoeconomic analyses were performed at various operating loads to determine the best operating load of each turbocharger. Energy analysis indicated that the most heat loss occurred at exhaust gases in higher load. Exergy analysis pointed out that the most exergy destruction appeared in the engine block in all tests conducted. In addition, thermoeconomic and exergoeconomic parameters increased in higher load.

Maintenance of the N47 Internal-Combustion Diesel Engine

The N47 engine debuted in March 2007 in the facelifted BMW 1 Series E87 and E81 and was also available in the BMW 1 Series E82 and E88, which were introduced the same year. The N47 engine replaced the M47 engine that had been in production for 8 years. The M47 construction underwent several modifications, so the injection system was changed, the cylinder head now consists of two parts, and the engine block is made of aluminium. Two main versions of the N47 engine are known: N47D16 (1.6 L) and N47D20 (2.0 L). In the case of both versions, several models with different performances were born. After the distribution of BMW passenger cars equipped with the N47D20 engine, it received a lot of negative criticism due to malfunctions. In this article, I would like to present the maintenance of the engine, which can be used to avoid the failure of passenger cars equipped with the N47D20 diesel engine with huge material damage.

Influence of cutting parameters on end milling of magnesium alloy AZ31B

Magnesium alloys are having the characteristics like light weight, wear, and corrosion resistance. Mg alloys find usage in a wide range of applications such as engine block of automobile parts, laptop cases, aircraft fuselages and mobile outer cases. However, in dry machining, many challenges restrict its development during fitment. In this research work, conventional vertical milling machine was used to conduct end milling operation on Mg AZ31B alloy with coated carbide insert. End milling operations were performed by varying spindle speed, feed per tooth, and constant cutting depth. The chip morphology and tool chip interface temperature were investigated for various cutting conditions. Also, feed force (Fx), thrust force (Fy) and cutting force (Fz) was analyzed to understand the proper material deformation characteristics.