Specific Grinding Energy Research Articles

Online prediction of grinding wheel condition and surface roughness for the fused silica ceramic composite material based on the monitored power signal

The fused silica ceramic matrix composite (SiO2f/SiO2) is characterized as one of the most promising materials in radar radomes and wave-transparent antenna windows. However, the ceramic matrix surface is rather rough, which reduces their service life in severe environments. Although precision grinding is used to improve surface quality, it gets difficult to precisely achieve the desired surface requirement due to the SiO2f/SiO2 material hardness, brittleness, and complicated fiber structure, as well as the uncertain wheel conditions. Especially the wheel condition and its influence on surface quality are unable to quantify directly. With the fast development of IoT monitoring and cyber-physical system, online prediction using process physics signals gains more interest. Power monitoring is a convenient way to obtain valuable grinding information at a relatively lower cost, making it more popular in the industry. However, the links between grinding parameters, power signal, and wheel conditions, surface quality is unclear. A series of grinding experiments of the SiO2f/SiO2 workpiece has been designed to demonstrate how the wheel conditions are indicated using the warm-cold density chart of specific grinding energy. A novel exponential polynomial model of surface roughness associated with wheel conditions indicated by the cutting power signal has been built. Compared with the conventional prediction model, REs center, MSE, and Pearson correlation coefficient are improved significantly from −0.0213, 0.029669, and 0.8695 to 0.0022, 0.022478, and 0.8710, respectively.

Surface roughness and morphology evaluation of bearing steel after grinding with multilayer graphene platelets dispersed in different base fluids

Bearings are widely used in different industries which demand different quality requirements to ensure a long life with low wear rates. In this sense, bearing components should present combination of low surface roughness and tight dimensional deviations, as well as good lubricant retention capacity. So, grinding is an alternative to achieve this combination, however, one of the challenges is the large amount of heat generated in the grinding wheel-workpiece interface when using conventional abrasives grinding wheels, which can lead to surface finish deterioration and thermal damages, thereby reducing the component's life. Thus, several cooling-lubrication techniques have been tested in the past decades to enhance the cooling-lubrication properties of cutting fluids, with a highlight in recent years for the benefits of adding solid particles with good tribological properties to improve grinding efficiency. In this context, this work sought to evaluate the roughness and surface morphology of the bearing steel SAE 52100 (60 ± 2 HRC) after grinding with multilayer graphene (MLG) platelets dispersed in two different cutting fluids (synthetic and semi-synthetic). Tests with traditional MQL (without solid particles) and conventional techniques (flood) were also carried out for comparison. The output variables investigated were surface roughness parameters Ra, Rz, Rku, Rsk, Rk, Rpk, and Rv, images of machined surfaces through a scanning electron microscope (SEM), and the specific grinding energy. The results indicated that the base fluid type significantly affected the grinding performance. Tests with semi-synthetic fluid having MLG decreased the Ra parameter of the ground surface by 9% compared to the traditional MQL technique, with a higher Rvk and negative skewness. For the synthetic fluid also with MLG, about 29% increase in the Ra parameter was observed compared to MQL without nanoparticles, although it resulted in higher values of Rpk with more positive skewness. Presence of MLG in semi-synthetic and synthetic fluids reduced the specific grinding energy by 7% and 14%, respectively. Also, less intense plastic deformation and material adhesion was observed when grinding with MLG.

Key technologies for laser-assisted precision grinding of 3D C/C-SiC composites

Due to their exceptional and distinctive qualities, 3D C/C-SiC composites are widely utilized in producing high-end equipment and the aerospace national defense industries. However, the hard and pseudo plastic nature of the material and its anisotropies make it challenging to process. To improve the processing quality of 3D C/C-SiC composites, laser-assisted precision grinding technology is introduced in this paper, which innovatively controls the depth of the thermally induced damage layer by adjusting the laser process parameters to reduce the hard brittleness of the material, and then the surface is created by precision grinding with a grinding wheel on this basis. Experiments on laser-induced damage, laser-assisted grinding, and diamond scratching were carried out to investigate the effect of laser parameters on material damage and the effect of laser-assisted grinding processes, with an emphasis on revealing the mechanism of material removal. The results show that laser irradiation causes complex reactions such as sublimation, decomposition, and oxidation of 3D C/C-SiC composites, resulting in SiO2 and Si and recondensed SiC, causing surface/subsurface damage. A maximum reduction in normal grinding force, tangential grinding force, specific grinding energy, and surface roughness of 35.6%, 43.6%, 43.58%, and 24.22%, respectively, compared to conventional grinding processes with laser-assisted grinding. After laser irradiation, the degree of brittle fracture in the precision grinding of workpieces is significantly reduced due to the degradation of matrix and fiber damage caused by laser irradiation, which reduces the hard and pseudo plastic properties of the material. The removal mechanism shows a trend of ductile domain removal in the grinding of thermally damaged layers, which reduces the grinding force and improves the surface quality.

Effectiveness of using liquid nitrogen cryogen in grinding to enhance the grinding performance of hard steel

Grinding generates a lot of heat in the grinding zone area during operation. Therefore, it is important to keep the temperature under control by using various cutting fluids to get a good ground surface quality. The existence of a stiff air layer surrounding the abrasive wheel is known to waste most of the cutting fluid supply in the interface area between the abrasive wheel and workpiece. Due to the high grinding speed, stiff air layers prevent cutting fluids from entering the interface area. Hence, to enhance the grinding performance, cryogenic cooling has been introduced to improve the penetration into the stiff air layer. The current work investigates the grindability of the ground surface of AISI D2 tool steel under different environments: dry, wet, and cryogenic, regarding grinding forces (i.e. tangential and normal force), specific grinding energy, and surface characterisation. This paper also proposed a method to evaluate image-based Abbott–Firestone curve (bearing area curve) parameters to characterise the ground surface topography. Significant reductions in grinding forces (64%–67% and 44%–50% in Ft, 54%–58% and 34%–39% in Fn), low specific grinding energy (64%–67% and 44%–50%), decrease in surface roughness (46%–51% and 30%–36% in Ra, 37%–41% and 31%–35% in Rz), improved 2D and 3D roughness profiles and higher bearing area ratio (89.54%) were observed at 40 µm downfeed in cryogenic cooling environments compared to dry and wet environments, respectively. Thus, observations show the importance of cryogenic cooling across the experimental domain.

Comparative investigation of laser assisted hybrid microgrinding methods

• LAMG and AILAMG methods were compared with CMG. • Grinding force, roughness, MRR, specific grinding energy and surface morphology were analyzed. • LAMG and AILAMG’s surface microstructure were changed due to thermal effect. Hybrid micro-grinding is an emerging area for high-quality microstructure fabrication and performance improvement. This paper describes the novel approach of hybrid microgrinding methods, i.e., laser-assisted micro-grinding (LAMG) and air induced laser assisted micro-grinding (AILAMG). Laser assistance before grinding weakens the material bond in LAMG. Further, during the AILAMG process, air assistance helps to create a loose oxide layer and propagate cracks on the surface. The experimental results show specific grinding energy reduced by 78% and 58% in AILAMG and LAMG, respectively, compared to conventional micro-grinding (CMG). Similarly, forces were reduced by 58% and 31%, respectively. The roughness has a minor increase in both methods compared to the CMG.

Analysis of grain tribology and improved grinding temperature model based on discrete heat source

A high grinding temperature will cause thermal damage to a workpiece surface and deterioration of surface integrity, which is the bottleneck of grinding. The present grinding temperature theoretical model is based on grain homogeneity and the continuous heat source distribution in the grinding zone. However, the random change in interference between the effective grains and a workpiece during the machining process causes a change in the grain tribological properties, resulting in varying transient grinding temperatures. Based on the current situation, the grain tribological mechanism and an improved temperature model based on a discrete heat source are proposed to reveal the temperature variation law of a workpiece in an actual grinding process. First, the surface topography model of a grinding wheel is established based on the geometric characteristics of grains, and the determination mechanism of effective grains is revealed. Furthermore, the interference mechanical behavior of the grains and workpiece is analyzed according to the kinematic law of grains in the sliding, plowing, and cutting stages. The mechanical model and specific grinding energy model at different stages are established, and the thermal distribution mechanism of effective grains is revealed. Finally, a temperature field mathematical model of a discrete heat source is established, and numerical simulation is performed to demonstrate the dynamic temperature change process of different grains. A new experimental method for measuring temperature at different positions of the workpiece with a bipolar thermocouple array is designed, and a regional numerical simulation and experimental temperature comparison method is innovatively proposed. Experimental results show that the grinding temperature measured under different cutting depth conditions is in good agreement with the numerical results, and the variation law is consistent. The minimum error in 64 groups of experimental measuring and numerical calculation comparison zones can reach 4.9%, and the proportion of zones with errors less than 10% can approach 86%. This study will provide a theoretical basis for the accurate suppression of workpiece surface thermal damage and the development of precision grinding in engineering discipline and machinery industry.

Optimization of Grinding Parameters of Tool Steel by the Soft Computing Technique.

Grinding is one of the most complex and accurate machining processes, and the efficiency of the grinding wheel depends significantly on its surface properties. This work aims to propose an algorithmic manner that reduces the cost and time to conduct grinding of an optimized DIN 1.2080 tool steel (SPK) using a soft computing technique to obtain the best combination of input parameters including depth of cut (20, 40, 60 μm), wheel speed (15, 20, 25 m/s), feed rate (100, 300, 500 mm/s), and incidence angle (0, 30, 45 de grees) with respect to output parameters consisting of average surface roughness and specific grinding energy. According to the input parameters and their levels, an experiment using fractional factorial design of experiment (RFDOE) was designed. Later on, two parallel feed-forward backpropagation (FFBPNN) networks with similar topology made up of 4, 11, and 1 units in their input, hidden, and output layers are trained, respectively. After sensitivity analyses of networks for determination of the relative importance of input variables, a genetic algorithm (GA) adopting linear programming (LP) based on Euclidean distance is coupled to networks to seek out the best combinations of input parameters that result in minimum average surface roughness and minimum specific grinding energy. The findings revealed that RFDOE provides valid data for training FFBP networks with a total goodness value of more than 1.99 in both cases. The sensitivity analyses showed that feed rate (38.97%) and incidence angle (33.94%) contribute the most in the case of average surface roughness and specific grinding energy networks, respectively. Despite the similar surface quality based on scanning electron microscopy (SEM), the optimization resulted in an optimized condition of the depth of cut of 25.23 μm, wheel speed of 15.02 mm/s, feed rate of 369.45 mm/s, and incidence angle of 44.98 de grees, which had a lower cost value (0.0146) than the optimum one (0.0953). Thus, this study highlights that RFDOE with a hybrid optimization using FFBP networks-GA/LP can effectively minimize both average surface roughness and specific grinding energy of SPK.

Material removal mechanism of SiC ceramics by elliptic ultrasonic vibration-assisted grinding (EUVAG) using single grain

The variation laws of grinding force, grinding specific energy, material removal rate, scratch morphology, and smooth surface ratio are investigated from the perspectives of wheel speed and undeformed chip thickness to study the material removal mechanism of elliptic ultrasonic vibration-assisted grinding (EUVAG) of SiC ceramics. First, the characteristics of undeformed chip thickness are analyzed based on the trajectory of grain in EUVAG. Then, a comparative experiment of EUVAG and conventional grinding (CG) with SiC ceramics of single diamond-grain scratches is conducted. Experimental results show that EUVAG plays a significant role in reducing grinding force and specific energy, which improves the material removal rate compared with CG. The grinding force is proportional to the undeformed chip thickness, and the grinding force ratio (normal force/tangential force) ranges from 3.8 to 9.8 under CG and from 2.2 to 7.1 under EUVAG. With the increase in wheel speed, grinding force increases first, then decreases, and finally increases again. As a whole, the grinding specific energy decreases with the increase in undeformed chip thickness, and it rises with the increase in wheel speed. The overall decrease in grinding specific energy under CG is more drastic, and the variation range is about three times of that at EUVAG. When the wheel speed is small or undeformed chip thickness is increased, MRR of EUVAG can be increased by about 30% compared with CG. The larger wheel speed and the smaller undeformed chip thickness all have an inhibitory effect on the line broken. The undeformed chip thickness is the primary affecting factor of the smooth surface ratio, followed by elliptic ultrasonic vibration, and the wheel speed has the smallest effect.

Analysis of grinding mechanics and improved grinding force model based on randomized grain geometric characteristics

Too high grinding force will lead to a large increase in specific grinding energy, resulting in high temperature in grinding zone, especially for the aerospace difficult cutting metal materials, seriously affecting the surface quality and accuracy. At present, the theoretical models of grinding force are mostly based on the assumption of uniform or simplified morphological characteristics of grains, which is inconsistent with the actual grains. Especially for non-engineering grinding wheel, most geometric characteristics of grains are ignored, resulting in the calculation accuracy that cannot guide practical production. Based on this, an improved grinding force model based on random grain geometric characteristics is proposed in this paper. Firstly, the surface topography model of CBN grinding wheel is established, and the effective grain determination mechanism in grinding zone is revealed. Based on the known grinding force model and mechanical behavior of interaction between grains and workpiece in different stages, the concept of grain effective action area is proposed. The variation mechanism of effective action area under the influence of grain geometric and spatial characteristics is deeply analyzed, and the calculation method under random combination of five influencing parameters is obtained. The numerical simulation is carried out to reveal the dynamic variation process of grinding force in grinding zone. In order to verify the theoretical model, the experiments of dry grinding Ti-6Al-4 V are designed. The experimental results show that under different machining parameters, the results of numerical calculation and experimental measurement are in good agreement, and the minimum error value is only 2.1 %, which indicates that the calculation accuracy of grinding force model meets the requirements and is feasible. This study will provide a theoretical basis for optimizing the wheel structure, effectively controlling the grinding force range, adjusting the grinding zone temperature and improving the workpiece machining quality in the industrial grinding process.

Effect of intermittent cutting behavior on the ultrasonic vibration-assisted grinding performance of Inconel718 nickel-based superalloy

Ultrasonic vibration-assisted grinding (UVG) is a promising precision machining method for difficult-to-cut materials. This study investigated the intermittent cutting behavior in UVG of Inconel718 nickel-based superalloy and its effect on the grinding temperature, grinding force and workpiece surface quality. A novel material removal probability model was established to analyze the impact depth and the contact length between the abrasive grain and the workpiece considering the interference of grinding trajectories in UVG. Results indicated that the intermittent cutting behavior in UVG caused a decrease in the contact length by 42%, resulting in a significant reduction of grinding temperature and grinding force by 40% and 41%, respectively. It was suggested that the increase in the cutting depth was better than the increase in the workpiece infeed speed for enabling the lager material removal rate in the tangential UVG due to the lower grinding force ratio and the less change of specific grinding energy. A specific surface texture was generated on the ground surface due to the phenomenon of frequent contact and separation, enabling the reduction of workpiece surface roughness by maximum 20%.

IMPROVING THE EFFICIENCY OF FINISHING

The issues of finishing operations of machining and providing a reasonable choice of optimal options, taking into account the distribution between the removal of material by the tool and the friction of the ligament at the contact. At the same time it is necessary to ensure the greatest possible protrusion of the tops of the grains above the level of ligament of the circle, as well as the timely removal of blunt grains from the working surface of the circle. The use of tools with increased physical and mechanical capabilities for processing with exfoliation of the surface layer of the workpiece is proposed. The essence of the process is that it concentrates all the removal of material on a narrow contact length, while providing maximum speed with the lowest specific grinding energy. When grinding by exfoliation in the area of removal of the removal allowance is an order of magnitude higher than when conventional grinding. The contribution of friction and plowing energy becomes a small part of the total specific energy of grinding. The heat released during grinding is reduced, its dissipation conditions in the process of spot grinding are improved. These studies allow us to understand the physical essence of the process, to determine the modes of processing, as well as ways to optimize the technological parameters of spot grinding

The effects of grit properties and dressing on grinding mechanics and wheel performance: Analytical assessment framework

This paper introduces an analytical assessment framework for evaluating grinding wheel performance derived from the model of cutting and sliding grinding force components. Four new parameters are proposed based on wheel topography. These parameters are normalized through the aggressiveness number, which circumvents the influences of grinding geometry and kinematics. The framework is validated through experiments with different wheel topographies obtained by changing dressing conditions and grit properties (toughness, thermal stability and shape). The framework and experiments quantify how wheel wear flat area influences the sliding component and how grit protrusion influences the intrinsic specific grinding energy. This framework provides a rational basis for evaluating grinding-wheel performance and abrasive-grit selection.

Environmentally friendly grinding of C/SiCs using carbon nanofluid minimum quantity lubrication technology

The influences of dry grinding (DG), wet grinding (WG) and carbon nanofluid minimum quantity lubrication (CN-MQL) on the grinding performances of ceramic matrix composites are investigated in this paper. Thermal imager and thermocouple results show that the cooling effect of CN-MQL with a carbon concentration (C) of 5 g/L is not weaker than that of WG. The maximum temperature of 5 g/L CN-MQL is 250.41 °C, compared to 336.98 °C for DG. This configuration also results in the minimum surface roughness and grinding force. Normal grinding force Fn and surface maximum height difference Sz decrease from 44.9 N to 8.44 μm for DG to 20.3 N and 4.13 μm, respectively. The corresponding grinding performance is also substantially better than that of WG. The grinding surface morphology shows that CN-MQL is conducive to obtaining surface morphology with few surface defects. The specific grinding energy results show that the energy consumed by CN-MQL is significantly reduced when removing the same volume of material. Based on a comprehensive analysis of the grinding performance parameters, there is an optimal value of C. At lower values, a uniform and dense film cannot be formed between the abrasive tool and the workpiece. At higher values, the particles agglomerate, and the performance is reduced. The experimental results show that the optimal C is 5 g/L. Considering the high pollution and high cost of grinding fluids, CN-MQL technology has the advantages of a simple preparation process, green and pollution-free properties, and no professional disposal requirements. CN-MQL is also conducive to reducing energy consumption in the processing approach. This research shows that CN-MQL has good application prospects for grinding processes.

Experimental study on ultrasonic vibration-assisted grinding of hardened steel using white corundum wheel

The combination of ultrasonic vibration-assisted grinding (UVAG), the ultrasonic vibrating method, and the conventional grinding (CG) process is proposed to improve the grindability of hardened steel in the CG process. Comparative investigations on grinding force, temperature, and specific grinding energy for both grinding processes were conducted. In addition, the morphologies of the wheel wear and ground surfaces were also studied. Findings show that compared with the CG processes, the normal and tangential grinding forces in UVAG are reduced greatly by 16.44% and 17.44%, respectively. The UVAG process decreases the specific grinding energy by 8.30% owing to the increase of the maximum undeformed chip thickness and the grinding temperature by 19.01% due to the improvement of the coolant heat transfer capacity in the grinding arc zone. Meanwhile, the promising grain sharpness of wheels can be guaranteed from the enhanced cooling function on the grinding arc zone and the grain’s micro-fracture caused by ultrasonic impacting actions.

Energy-Model and Life Cycle-Model for Grinding Processes of Limestone Products

Fine and ultrafine grinding of limestone are frequently used in the pharmaceutical, chemical, construction, food, and cosmetic industries, however, research investigations have not yet been published on the combination of energy and life cycle modeling. Therefore, the first aim of this research work was the examination of main grinding parameters of the limestone particles to determine an empiric energy-model. Dry and wet grinding experiments have been carried out with a Bond mill and a laboratory stirred ball mill. During the grinding processes, the grinding time and the filling ratio have been adjusted. The second goal of this research assessed the resources, emissions and environmental impacts of wet laboratory grinding with the help of life cycle assessment (LCA). The life cycle assessment was completed by applying the GaBi 8.0 (version: 10.5) software and the CML method. As a result of research, the determination of an empiric energy-model allowed to develop an estimated particle size distribution and a relationship between grinding fineness and specific grinding energy. The particle size distribution of ground materials can be exactly calculated by an empirical Rosin–Rammler function which represented well the function parameters on the mill characters. In accordance with LCA results, the environmental impacts for the mass of a useful product for different levels of specific energy with the building of approximation functions were determined. This research work sets up a new complex model with the help of mathematical equations between life cycle assessment and specific energy results, and so improves the energy and environmental efficiency of grinding systems. This research work facilitates the industry to make predictions for a production-scale plant using an LCA of pilot grinding processes.

Pore morphology design and grinding performance evaluation of porous grinding wheel made by additive manufacturing

Open porous structure is of great importance for metal-bonded grinding wheel but hard to realize with traditional hot pressing and sintering process. In this article, a novel design and fabrication method of porous metal-bonded grinding wheel is proposed based on triply periodic minimal surfaces and additive manufacturing. The control method of pore morphology is specifically studied in terms of pore connectivity constraint condition and parametric control equation. With control equation, the porosity, equivalent aperture, relative density, specific surface area and pore connectivity of porous structure can be accurately controlled and predicted under given design parameters. With additive manufacturing, porous metal-bonded grinding wheel with well-formed pores and firmly-embedded abrasives can be realized. The grinding test results indicate that the novel porous metal-bonded grinding wheel behaves better than electroplated wheel in terms of grinding force and specific grinding energy. The proposed method can realize the design and fabrication of metal-bonded grinding wheel with large porosity and open porous structure, so as to effectively improve the problems such as surface blockage and grinding burn.

A comparative analysis of grinding of AISI D2 tool steel under different environments

Difficult-to-cut material, i.e., AISI D2 tool steel, has been widely adopted in metalworking industries to manufacture dies for piercing, blanking, drawing and thread rolling due to its excellent wear resistance and non-deforming properties. This article attempts an experimental study to determine the effect of cryogenic coolant (liquid nitrogen) on the grindability of AISI D2 tool steel as work material and its results are compared with the conventional dry and wet grinding methods. The effects of the cryogenic coolant on force components (i.e., tangential force, Ft and normal force, Fn ), specific grinding energy (u), force ratio, surface roughness parameters (Ra and Rz ) and microstructure were observed. The comparison results indicate a significant reduction in grindability indices such as 64% and 44% in Ft , 54% and 34% in Fn , 46% and 30% in Ra and 40% and 34% in Rz , respectively under cryogenic grinding at higher downfeed as followed to dry and wet grinding. The grinding performance in Ft , Fn , u and Ra was also improved with an increased delivery pressure of the liquid nitrogen (LN2). From the results, it is concluded that cryogenic coolant offers an influential method to improve grinding performance and surface integrity of AISI D2 tool steel.

Modeling of strain gradient-dependent strengthening effect in grinding of boron-diffusion-hardened titanium alloy

In grinding of the boron-diffusion-hardened titanium alloy, with the grinding speed increasing, the strain gradient-dependent strengthening (SGS) effect of TiB whiskers would become obvious, resulting in an improvement of the surface quality. To explore such SGS effect of TiB whiskers, a novel model of the strain gradient-dependent strengthening effect in the primary deformation zone was developed, and then a novel specific grinding energy model was further proposed to quantitatively estimate such SGS effect of TiB whiskers. It indicates that the above two models can adequately demonstrate the SGS effect of TiB whiskers in grinding the borided titanium alloy. The results demonstrate that the grinding performance of the borided titanium alloy was dominated not only by the grinding speed but also by the TiB whiskers. Due to high grinding speed (about 120 m/s) inclining to cause the maximum undeformed chip thickness reduced, when it was closed to the size of TiB whiskers, the SGS effect of TiB whiskers would become obvious, leading to an improvement of surface quality. Furthermore, when the size of TiB whiskers was closed to the sub-micron-scale, the enhanced SGS effect of the sub-micro-sized TiB whiskers tends to generate, causing the surface quality further improved.

Processing and machining mechanism of ultrasonic vibration-assisted grinding on sapphire

Owing to outstanding mechanical, optical, thermal stability and chemical stability properties, sapphire has widespread use in semiconductors, aerospace and other fields. However, it is difficult to machine it efficiently and precisely because of its brittleness and hardness. In this work, the processing and mechanism of machining sapphire using ultrasonic vibration-assisted grinding technology have been investigated via experiment. The machining factors have been analyzed, including the condition of machined surface, specific grinding energy, force and force ratio. Referring to conventional grinding, the application of ultrasonic vibration reduces the force, force ratio, specific energy, and the reduction ratio is direction dependent. The effect on surface roughness and morphology is also anisotropic. Regarding the smoothness of the surface, the suitable directions were axial and tangential, while there was no noticeable improvement in the radial direction. Our results and insights could be beneficial for the precise machining of brittle materials and quality management.

On reduction of energy flow into workpiece in continuous generating grinding

Owing to intense heat generation in the continuous generating grinding, a large amount of grinding fluid is supplied during the process. Recently, however, reduction in grinding fluid supply has been attempted. In this study, the specific grinding energy and heat partition ratio of continuous generating grinding was analysed under dry conditions. The results revealed that the specific energy reduced to 53.8% with the grinding wheel of nine starts compared to that of three starts. The heat partition ratio remained almost unchanged with varying number of starts. The results revealed that a wheel with higher number of starts is thermally beneficial.