Groove Height Research Articles

Systematization of the Brain Base Arteries in Nutria (Myocastor coypus)

Background: The nutria (Myocastor coypus) is a medium-size, semi-aquatic rodent, valued in skin and meat industry. The brain circulation has been well studied in rodents but not in nutria. To understand and compare the phylogenetic development of the arteries of the base of the brain in rodents, this paper aims to describe and systematize these arteries, establishing a standard model and its main variations in nutria.Materials, Methods & Results: Following approval by the Ethics Committee of Federal University of Rio Grande do Sul, thirty nutrias from a commercial establishment authorized by Brazilian Institute of Environment and Natural Resources (IBAMA) were studied. For euthanasia, was applied heparin (10000 U.I for animal), intraperitoneally, and after thirty minutes the animals ware sedated with acepromazine (0.5 mg/kg) and meperidine (20 mg/kg), intramuscularly. After sedation, they were euthanized with thiopental sodium (120 mg/kg) and lidocaine (10 mg/mL), intraperitoneally. The heart was accessed, the cardiac apex was sectioned, the aorta was cannulated via the left ventricle and clamped close to the diaphragm, and the arterial system was washed with saline solution and filled with latex. The animals were submerged in water for latex polymerization, the trunk was sectioned, the skin removed and a bony window was opened in the skull vault. The pieces were fixed in formaldehyde. The brains were removed, and schematic drawings of the arteries from the base of the brain were made for elaboration of the results. The nutria’s brain was vascularized by the vertebro-basilar system. The terminal branches of the right and left vertebral artery were anastomosed on the ventral surface of the medulla oblongata, forming the basilar artery, and caudally the ventral spinal artery. The basilar artery formed collateral branches, the caudal and middle cerebellar and trigeminal arteries, and at the height of the rostral pons groove, divided into its two terminal branches, the rostral cerebellar and cerebral caudal arteries. The terminal branches of the basilar artery projected rostrally, forming the hypophyseal and rostral choroid arteries. The basilar artery passed the optic tract and bifurcated in the middle cerebral artery, its last collateral branch, and in the rostral cerebral artery, its terminal branch. The rostral cerebral artery formed the medial branch, closing the cerebral arterial circle caudally in 40% of the cases.Discussion: In rodents, variability of the cerebral arterial circle was observed due to the degree of atrophy of the internal carotid artery. The basilar artery was a rectilinear vessel of great caliber in all described rodents, and in rodents with a vertebro-basilar system, it was divided into its terminal branches after crossing the pons, forming the rostral cerebellar, hypophyseal, rostral choroid, caudal, middle and rostral cerebral arteries. The caudal cerebellar artery had variation of origin and sometimes duplication. The median cerebellar artery, a collateral branch of the caudal cerebellar artery, was a branch of the basilar artery in capybara. The caudal cerebral artery had variations between rodents. In capybara, chinchilla and nutria the middle cerebral artery was the collateral branch of the terminal branches of the basilar artery, and distributed on the convex surface of the cerebral hemisphere. The rostral cerebral artery, a branch of the terminal branch of the basilar artery, was a branch of the internal carotid artery in other rodents, forming the medial branch, which was anastomosed with that of the opposite antimer, when present, forming the rostral communicating artery. In nutria, the cerebral arterial circle was closed caudally in all cases, as in other rodents, however, it was opened rostrally in 60% of cases, compared to 70% in chinchilla and 10% in capybara.

Analysis of constrained groove pressing and constrained groove pressing-cross route process on AA5052 sheet for automotive body structure applications

In this paper, a hybrid experimental-numerical approach was developed to analyze the constrained groove pressing and constrained groove pressing–cross route process on AA5052 sheets which are comprehensively used to produce body in white and closure panels and beams of the automotive. The microstructure and mechanical properties were evaluated using scanning electron microscopy, tensile tests, and microhardness measurements. Then, the developed procedure was used to predict the mechanical properties of the sheets fabricated by constrained groove pressing process. This enabled the evaluation of the effects of the groove angle, width, and height of the die on strength and hardness of the processed sheets. To complete the conceptual design of the grooved dies, the Taguchi method was used to optimize the die design. The obtained results show that the inhomogeneity factor in the sheets processed by constrained groove pressing–cross route is less than those processed by constrained groove pressing. The analysis indicates that the developed procedure would result in an acceptable prediction of the material behavior of the processed sheets. The procedure could save a great deal of time and is economical in the matter of design. Finally, the procedure in conjunction with Taguchi method would lead to an optimum die design to enrich the processed sheets.

Magnetic polariton enhanced broadband absorption and photoresponse of monolayer MoS2 based on normal and anomalous metallic gratings

A novel structure of two-dimensional MoS2, with normal and anomalous metallic Ag grating, is proposed to enhance the broadband absorption of monolayer (ML) MoS2 and the photoresponse of MoS2-based photodetectors. The basic physical mechanism of both the normal and anomalous Ag grating with ML MoS2 is understood by studying the magnetic field distribution. The simulation results indicate that magnetic polaritons (MPs) with different orders could form different absorption peaks, and the same-order MPs with different groove heights can also form different absorption peaks, which can meet the expectations of achieving broadband adjustable absorption. Equivalent inductor capacitor circuit theoretical models are adopted to further verify the physical mechanism and resonance conditions of MPs in the structures of normal and anomalous metallic Ag gratings with ML MoS2, demonstrating that the theoretical calculations agree well with the simulation results. The effect of grating geometry for the absorption and photoresponse enhancement of ML MoS2-based photodetectors is also investigated, indicating that anomalous metallic gratings are more effective at achieving broadband absorption and an enhanced photoresponse of ML MoS2 compared with that of normal metallic gratings.

Generation of multiband spoof surface acoustic waves via high-order modes

Through theoretical analysis and numerical calculation, it is found that the textured surface of a perfect rigid body whose groove height is sufficiently large can support multiple modes of propagating spoof surface acoustic waves (SSAWs). Dispersion curves and group velocities/refractive index versus height and width of the groove are depicted for infinitely thick perfect rigid body to make a thoroughly inquiry into the multiband transmission of SSAWs. We also give the dispersion relations of samples with finite thickness which are more practical to realize, and the corresponding experimental results are in accordance with simulated results. Theoretical, simulated, and measured acoustic pressure field distributions are given to further illustrate the characteristics of different modes. Our work could have implications for applications such as acoustic filter design and energy harvesting.

The influence of structural parameters on heat transfer and pressure drop for hydrocarbon mixture refrigerant during condensation in enhanced spiral pipes

In this paper, the condensation heat transfer and pressure drop characteristics for hydrocarbon mixture upward flow in smooth and enhanced spiral pipes were numerically investigated. The numerical model was established and verified by experimental results in literatures. It discussed the influence of geometrical parameters on condensation heat transfer and pressure drop in three kinds of enhanced spiral pipes, which contained square corrugated pipe, sinusoidal corrugated pipe and spiral grooved pipe. The results indicate that in enhanced spiral pipes, both frictional pressure drop and heat transfer coefficient increase with the rise in corrugation (groove) height and the decrease of corrugation (groove) pitch. Meanwhile, compared to the smooth pipe, the augmentation on heat transfer for square corrugated, sinusoidal corrugated and spiral grooved pipes are 0.934–2.052, 1.103–2.216 and 1.206–1.804 times, respectively, while the increase of frictional pressure drop are 1.805–10.930, 1.272–7.176 and 0.851–3.587 times, respectively. Besides, the comprehensive heat transfer enhancement factor (CHF) was introduced to evaluate the overall heat transfer performance of enhanced pipes. It is found that as the corrugation (groove) height increases, the CHF increases in square and sinusoidal corrugated pipes but decreases in spiral grooved pipe; at the meantime, with the increase of corrugation (groove) pitch, the CHF first decreases and then increases in square and sinusoidal corrugated pipes while first increases and then decreases in spiral grooved pipe. The average CHFs for all square corrugated pipes, sinusoidal corrugated pipes and spiral grooved pipes are 0.872, 1.083 and 1.275, respectively. Moreover, the spiral grooved pipe with the relative groove height and pitch of 0.03535 and 5.0 shows the best overall heat transfer performance among others, whose average CHF can reach to 1.413. These results provide some instructions for the application of enhanced spiral tube in the design of spiral wound heat exchange (SWHE).

Finite Element Analysis of Sealing Performance of Rubber D-Ring Seal in High-Pressure Hydrogen Storage Vessel

Sealing structures of high-pressure hydrogen storage vessel are always considered as one of the significant components. This paper aims to study the sealing performance of the combined sealing structure composed of a rubber D-ring and a wedge-ring used in high-pressure hydrogen storage vessel by elucidating the swelling mechanisms due to dissolved hydrogen. Comparisons of the sealing performance between the D-ring and the O-ring are made in terms of the effects of some important factors including the wedge-ring, hydrogen pressure and swelling. Three aspects of conclusions are obtained by FEA: (1) The wedge-ring with a wedge angle 45° is the most suitable, compared with the angles 30° and 60°, irrespective of the shape of rubber rings. (2) The peak contact stress for the D-ring seal is larger than that for the O-ring seal under hydrogen pressure range 0–100 MPa. (3) The O-ring seal could be replaced well by the D-ring seal, whereas the design height of the seal groove should be larger for the D-ring seal than for the O-ring seal due to swelling effect, in order to prevent the D-ring seal from extrusion through the upper side of the seal groove.

Performance analysis of plate-type vapor–liquid separators with groove used in marine desalination

Taking vapor–liquid separators used in marine desalination as objects, a novel kind of plate-type vapor–liquid separator with groove is designed to achieve a more prominent separation effect. The Eulerian–Lagrangian approach is applied to simulate the two-phase flow in the separator. The SST κ–ω turbulence model is utilized to simulate the continuous phase, and discrete phase model (DPM) is employed to calculate the water droplet distribution and the corresponding trajectories, which is verified by the experimental results from the literature. The impacts from the groove height, width and depth on the separator performance are studied. Furthermore, to acquire the optimal geometry of the separators with groove, a dimensionless objective function considering the space size, separation efficiency and pressure drop is proposed, and the corresponding prediction model is established based on the response surface methodology. Compared to the traditional type, the computational fluid dynamic (CFD) simulation results show that a higher velocity and bigger circulation region contribute to a much more comprehensive performance in the proposed separator. After determining the optimal values for all the parameters, a discrepancy value of 5.2% between the simulation results and the prediction value is attained, which indicates that the prediction model is applicable to guide the design of the separator. Further study shows that the optimal novel separator guarantees the separation efficiency with much smaller size compared with the original one.

Stability of the Poiseuille Flow in a Channel with Comb Grooves

The stability of the Poiseuille flow in a channel with longitudinal comb grooves on the lower wall is studied numerically. Dependences of the linear and energy critical Reynolds numbers on the groove spacing and height are obtained and analyzed. The results are compared with data available for wavy grooves, which tend to comb grooves as one of the groove parameters approaches infinity.

Uniform concentrating design and mold machining of Fresnel lens for photovoltaic systems

Fresnel lens arrays are widely applied as the core optical component in concentrated photovoltaic (CPV) systems for concentrating light on a solar cell. To improve the photoelectric conversion efficiency of CPV systems, a Fresnel lens design is proposed, in which both uniform concentration and machining feasibility are pursued by means of simpler structure. In this design, the concentrating facets of the Fresnel lens are conical ones with different inclined angles, and the light passing through these conical facets can be superposed on the same position. The optical performance of the lens is analyzed to optimize its geometrical parameters. Towards this uniform concentrating design with a simple structure, an ultra-precision diamond cutting process based on B axis rotation is also developed to machine the Fresnel lens mold. In this process, the V-shaped diamond tool is rotated from right to left to machine the micro grooves of the lens mold with a maximum cutting depth of the groove height, so that the grooves can be prevented from being cut by the tool tip with low strength. Cutting tests of the factors influencing the machining accuracy and surface quality are carried out to optimize the cutting trajectory planning and machining parameters. The Fresnel lens molds with no sharp corner defects and no surface scratches are machined, and dimensional accuracy of 1.0 μm and surface roughness of better than 13 nm are achieved. Then, a silicone rubber lens is cast based on this mold. Concentrating uniformity test of the lens is conducted, and a concentrating uniformity of better than 75% is achieved. The results show the effectiveness of the uniform concentrating design and the feasibility of the B axis rotating machining process.

Experimental Investigation on Flexural Behavior of Granite Stone Slabs with Near Surface Mounted CFRP Bars and Screw‐Thread Steels

An experimental study that investigates the behavior of stone slabs strengthened in fixure with near surface mounted (NSM) technique using screw‐thread steels and carbon fiber‐reinforced polymer (CFRP) bars is presented. A total of ten full‐scale stone slabs were tested under a four‐point bending loading to investigate the effect of groove dimension, reinforcement ratios, and reinforcement materials on the flexural performance of stone slabs. The test results included failure characteristics, yield and ultimate capacities, deflection of midspan, and cracking behavior of stone slabs. The test results indicate that with the increase of groove height and groove width, cracking load and middeflection decrease by 6.4%–14.18%; however, failure load and middeflection increase by 4.7%–41.2%. Cracking load, failure load, and failure displacement of stone slabs adopting NSM screw‐thread steels increased by 10.9%, 167%, and 617%, respectively, under the maximum reinforcement ratios of 0.629% over the control slab without NSM bars. Meanwhile, with the increase of reinforcement ratios, the failure mode transforms from brittle failure to ductile failure. The calculation results of strength are in agreement with the experimental results. Finally, it can be concluded that NSM CFRP bars are more effective than NSM screw‐thread steels to improve flexural capacity with the same reinforcement ratios.

Fabrication of Inner Grooved Hollow Fiber Membranes Using Microstructured Spinneret for Nerve Regeneration

Nerve conduits with topographical guidance have been recognized as the efficient repair of damaged peripheral nerves. In this study, polymeric hollow fiber membranes (HFMs) with grooved inner surface have been fabricated from a microstructured spinneret using a dry-jet wet spinning process for nerve regeneration studies. The effectiveness of HFM inner grooves has been demonstrated during an in vitro study of chick forebrain neuron outgrowth. It is of great importance that the groove geometry can be controllable to meet various needs in promoting nerve regeneration performance. While the overall groove geometry is determined by the spinneret design, fabrication conditions are also indispensable in fine-tuning the final groove geometry such as the groove height and width on the order of 10 μm or less. It is found that the bore fluid flow rate can be utilized to effectively adjust the resulting groove height by at most 52% and groove width by at most 61%, respectively, without modifying the spinneret geometry. This enables a new approach to fabricate different grooved HFMs using the same spinneret. By comparing to the influences of bore fluid flow rate, the dope fluid flow rate is less effective in regulating the groove height and width when using the same microstructured spinneret. Both bore and dope fluid flow rates should be carefully selected for fine groove width tuning.

Optimization and influence of the geometrical parameters of chip breaker for finishing machining of Fe-Cr-Ni stainless steel

In the metal cutting process, a blocked chip needs to be avoided as it leads to low tool life, poor machined surface quality, and large cutting force, whereas an unbroken chip may scratch the machined surface and hinder efficient chip removal in metal cutting. For finishing machining of Fe-Cr-Ni stainless steel, the chips will not be broken easily without chip breakers. Therefore, in this paper, two-dimensional (2D) finite element models of orthogonal cutting were built with finite element software, AdvantEdge, to optimize the chip breaker parameters for finishing machining of Fe-Cr-Ni stainless steel. An optimized methodology was proposed and the chip breaker was optimized based on chip curl radius, tool stress, temperature, and cutting force. The smaller groove height of chip breaker is recommended with low cutting speed and large feed rate, while the larger groove height of chip breaker is recommended with high cutting speed and small feed rate. Other chip breaker parameters were also optimized.

Optimization and test for structural parameters of UAV spraying rotary cup atomizer

Abstract: Small unmanned aerial vehicle (UAV) pesticide application technology is developing rapidly in China. However, the spray efficiency of UAV sprayer is not stable, one important reason is that the lack of specialized aviation nozzle. Rotary cup atomizer is not easily to be blocked and has broad application foreground in UAV spray. In order to obtain good spraying quality and narrow droplet spectrum aviation spraying centrifugal nozzle, the impacts of rotary cup atomizer structural parameters on atomization property were studied. In this research, a centrifugal atomization test device was designed, on which a frequency converter was used to adjust the rotary speed, and a return valve was used to stabilize the flow rate and pressure of spray liquid. The droplet volume medium diameter (VMD) and droplet spectrum relative width (SRW) were tested by using laser particle analyzer and particle analysis system. The analysis results of variance and quadratic regression orthogonal test were used to optimize the structural parameters of rotary cup atomizer. The influences of rotary cup atomizer structural parameters on atomization property, such as groove shape, diameter, teeth number, cone angle and height were evaluated and analyzed by conducting single-factor test. The results showed that: the best optimized rotary groove shape was square, diameter and teeth number had significant effects on droplet VMD and SRW, while cone angle had no effect on the droplet VMD and SRW, height affected droplet VMD but did not affect droplet SRW. Therefore, diameter and teeth number were selected as the variables of quadratic regression orthogonal test, droplet VMD and SRW regression model was established by using response surface analysis method. The optimized structural parameters respectively were: groove shape square, cone angle 60°, height 20 mm, diameter 61.5 mm and teeth number 149. Droplet VMD and SRW simulation value respectively were 200 μm and 0.562. The differences between simulation value and test value were 0.68% and 9.90% respectively, indicating that the regression model is accurate. The research result can provide a reference for further optimizing the structure parameters of rotary cup atomizer to meet the requirement of UAV spraying. Keywords: rotary cup atomizer, atomization, droplet VMD, droplet SRW, optimization, mathematical model, response surface DOI: 10.3965/j.ijabe.20171003.3119 Citation: Zhou Q Q, Xue X Y, Qin W C, Cai C, Zhou L F. Optimization and test for structural parameters of UAV spraying rotary cup atomizer. Int J Agric & Biol Eng, 2017; 10(3): 78–86.

HEAT TRANSFER ENHANCEMENT AND PRESSURE DROP OF GROOVED ANNULUS OF DOUBLE PIPE HEAT EXCHANGER

This investigation was performed to experimentally investigate the enhancement of heat transfer and the friction of an annulus in a double pipe heat exchanger system with rectangular grooves in the turbulent flow regime. The shell is made of acrylic and its diameter is 28 mm. The tube is made of aluminium and its diameter is 20 mm. Grooves were incised in the annulus room with a circumferential pattern, with a groove space of 2 mm, a distance between the grooves of 8mm and a groove height of 0.3 mm. The experiments consist of temperature and pressure measurement and a flow visualization. Throughout the investigation, the cold fluid flowed in the annulus room. The Reynold number of cold fluid varied from about 31981 to 43601 in a counter flow condition. The volume flow rate of hot fluid remains constant with Reynold number about 30904. Result showed the effect of grooves, which are applied in the annulus room. The grooves induce the pressure drop, the pressure drop in the grooved annulus was greater by about 15.88% to 16.72% than the one in the smooth annulus. The total heat transfer enhancement is of 1.09–1.11. Moreover, the use of grooves in the annulus of the heat exchanger not only increase the heat transfer process, but also increase the pressure drop, which is related to the friction factor.

Multi-objective optimization of surface textured journal bearing by Taguchi based Grey relational analysis

A multi-objective optimization approach is used to determine the optimal surface texturing parameters to improve performance of journal bearing. The numerical attempts are made using Taguchi's orthogonal array L27. Initially, static performance analysis is carried out for plain bearing system using thin film analysis by COMSOL Multiphysics and the results are validated with the literature. In the later part, analysis of load carrying capacity and frictional torque is carried out for different parameters of surface texturing. The bearing performance is studied for various groove parameters viz.groove location, groove height, groove width, number of grooves and spacing between grooves. Grey relational analysis is used to find an optimal set of parameters which gives maximum load carrying capacity and minimum frictional torque.

Ponticulus posticus: Morphometric analysis and Its anatomical Implications for occipito-cervical fusion

ObjectiveThe purpose of this study was to evaluate the morphometric characteristics of ponticulus posticus (PP) and determine the impact of two promising high cervical operations (posterior arch to lateral mass screw fixation (PALMSF) and occipital condyle fixation (OCF)). Patients and methodsWe evaluated retrospective data from a total of 2628 head and neck 3-dimensional CT-angiographies (3D-CTA) that did not have bony or vascular abnormalities. The PP anomaly cases were confirmed, then we measured vertebral artery groove height (VAGH), arch to vertebral artery distance (AVD) and posterior arch height (PAH) for PALMSF. We also measured the vertebral artery to occipital bone distance (VOD) for OCF. ResultsIn 186 patients (7.1%), 227 PP (complete or near complete) were identified and this anomaly was more common in males and on the left side. The mean VAGH and PAH values ranged from 5.0 to 6.0mm and from 7.0 to 8.8mm, respectively. The VAGH value was not statistically different, regardless of the presence of PP, and the feasibility (>4mm) of a safe PALMSF (range, 87.7–100%) was not influenced by PP anomalies. The mean value of VOD in the anomaly side (range, 6.0–8.0mm) was much higher than for normal side (range, 4.2–5.7mm) and the proportion of patients that had a safe OCF (>3.5mm) was also much higher (range, 90.8–96.9%) than for the normal side. ConclusionsA PP anomaly might have some anatomical feasibility and advantage during PALMSF and OCF, due to the relatively sufficient bony (VAGH) and spatial regions (VOD). However, there are gender differences in anatomical dimensions (VAGH, VOD and AVD); therefore, surgery in female patients should be approached more cautiously in the future.

The effects of groove height and substrate stiffness on C. elegans locomotion

The physical environment surrounding an animal has a significant impact on its behavior. The nematode Caenorhabditis elegans (C. elegans) has proved to be an excellent choice for understanding the adaptability of organisms crawling on soft surfaces. In this work, we investigate the modulation of C. elegans’ behavioral kinematics in response to changes in the stiffness of the substrate and study the effect of grooves incised by the worms on their locomotion speed and efficiency. We measure the height of the grooves created by the animals on surfaces with different rigidity using confocal microscopy. Our results indicate that the kinematic properties of C. elegans, including amplitude (A), wavelength (λ) and frequency (f) of head turns depend strongly on surface properties and the height of the grooves created by them. During crawling, we observe that the animal assumes two distinct shapes depending on the stiffness of substrates. As the stiffness increases, the worm’s body shape changes gradually from a ‘W’ shape, which is characterized by low amplitude curvature to the more common ‘S’ shape, which is characterized by high amplitude curvature, at intermediate values and back to ‘W’ on stiffer substrates. Although the efficiency is found to vary monotonically with surface stiffness, the forward velocity shows a non-monotonic behavior with the maximum on a surface, where the animal makes the ‘S’ shape.

Effects of Non-axisymmetric Casing Grooves Combined with Airflow Injection on Stability Enhancement of an Axial Compressor

AbstractThis paper presents a performance evaluation of non-axisymmetric casing grooves combined with airflow injection in a transonic axial compressor with NASA Rotor 37, using three-dimensional Reynolds-averaged Navier-Stokes equations with the k-ε turbulence model. An axisymmetric casing groove was divided circumferentially into 36 non-axisymmetric grooves. The numerical results for adiabatic efficiency and total pressure ratio were validated with experimental data. A parametric study for stall margin, stable range extension, peak adiabatic efficiency, and total pressure ratio at peak adiabatic efficiency of the compressor was performed using five parameters: the front and rear lengths, the height of the casing groove, the injection mass flow rate, and the injection angle. The non-axisymmetric casing grooves combined with injection improve greatly the stall margin and stable range extension of the transonic axial compressor, but reduce only slightly the peak adiabatic efficiency in all cases, compared to the results for a smooth casing.

ELUCIDATION OF LONGITUDINALLY GROOVED-RIBLETS DRAG REDUCTION PERFORMANCE USING PRESSURE DROP MEASUREMENTS

The need to determine affordable and environmentally friendly methods of reducing skin friction can be identified as one of the reasons contributing towards the study of the effectiveness of riblet shapes. Water tank experiments were carried out to optimize the shape and dimensions of microstructure grooves over a flat plate. The use of organized microstructures on channel walls is proposed to obtain lower values of pressure losses on smooth walls. Three shapes of microstructure grooves were investigated, with same groove height (600 μm) and five spacing dimensions (600, 750, 1000, 1500 μm), in water flows with velocities of up to 0.4 m/s. This was done for all selected types of riblet, which are fixed with the direction aligned with the flow. The experimental results showed that the size and shape of the riblets can massively incubate some of the turbulent structures formed on the surface and that will lead to a more controllable flow environment, which can result in drag reduction.

Effect of structure height on the drag reduction performance using rotating disk apparatus

The drag reduction characteristics in a rotating disk apparatus were investigated by using structured disks with different riblet types and dimensions. Two disk types were fabricated with right angle triangular (RAT) grooves and space v-shape (SV) grooves, with six dimensions for each type. A high-accuracy rotating disk apparatus was fabricated and then used to investigate the turbulent drag reduction characterization of the disk in diesel fuel. In this work, the effects of several parameters are investigated; riblet types, riblet dimensions, and rotational disk speed (rpm) on the drag reduction performance. It was found that the surface structure of the disk reduced the drag, this was clearly seen from the comparison of torque values of smooth and structured disks. Drag reduction for structured disks was higher than that for smooth disks, and SV-grooves showed better drag reduction performance than RAT-grooves. In addition, it was observed that the drag reduction performance increased with decreasing groove height for both groove types. The maximum drag reduction achieved in this study was 37.368% for SV-groove at 1000 rpm, compared with 30% for RAT-groove, at the same rotational speed.