Triangle Cross Section Research Articles

Design and dynamic analysis of a spanwise morphing wing for Mars exploration

The application of spanwise morphing wings makes it possible to transport and launch large-size Mars exploration UAVs. This article proposes a modular variable spanwise morphing wing for high-aspect-ratio aircrafts, and analyses the characteristics of the morphing wing by theoretical analysis, numerical simulation and experimental verification. The novel spanwise morphing wing is based on the Sarrus-inspired deployable structure, which can increase the wing's lift by changing the spanwise length. The pre-strain torsion springs are assembled to provide the initial driving moment of the morphing mechanism. A regular triangle cross section is selected by evaluating the bending and torsional stiffness, and deployable triangular prism mechanisms are identified. Through releasing the pre-strain torsion springs to achieve expansion and implant Sarrus linkages along the straight motion paths. A lockable structure is designed, and the main factors affecting the self-locking property are analysed. A rigid origami skin is proposed, which maintains the airfoil's continuous smoothness after spanwise morphing. The kinematics of the spanwise morphing wing unit is developed using the Lagrange equation, and the theoretical models of morphing wings with different numbers of units are obtained. The unit numbers influence fully expanded time, and the time decreases gradually along the wingtip's direction. Finally, a one-way fluid-structure interaction analysis is performed to investigate the spanwise morphing mechanism and origami skin response under aerodynamic loads. Results show that the skeleton mechanism's maximum stress is below the material's yield strength, and the origami skin's maximum out-of-plane deformation is less than 0.5% of the wing chord, which provides a necessary theoretical basis for applying the spanwise morphing wing.

Scale-dependent torsional frequency analysis of right triangle anisotropic advanced composite microscale rods

Despite several theoretical investigations on the torsional dynamic behavior of non-circular micro/nanorods, the torsional behavior of right triangle cross-section is still unevaluated. Therefore, Timoshenko-Gere theory in conjunction with nonlocal strain gradient theory is developed for modeling the scale-dependent torsional dynamic of right triangle microscale rods. Various anisotropic materials, i.e. hexagonal, trigonal, triclinic, and monoclinic materials are regarded as the constituent material of microscale rods. The shear stress function is developed for right triangle shape and according to the calculated shear stress function, the warping function of right triangle shape is obtained. The nonlocal governing equation of the torsional dynamic of anisotropic microrods is obtained with the help of the energy approach and solved using an analytical method by regarding two different boundary conditions. The accuracy of the proposed model is validated with recent similar investigations. Because of the lack of mechanical research on right triangle microrods, the proposed methodology was validated with equilateral triangle nanowire reported in the literature. Eventually, the various remarkable variants’ effects on change of scale-dependent torsional frequency are assessed comprehensively. It is found that hexagonal and triclinic materials have the largest and smallest values of frequency. Also, nonlocal parameter, b/h ratio play a decreasing role and length scale parameters and mode number plays an increasing role.

Directional BLUs for Full Resolution Field Alternative Auto-stereoscopic 3D/2D and 2D/3D LCDs

Switching-directional backlight units (BLUs) were designed and prototyped for full resolution field alternate auto-stereoscopic 3D liquid crystal displays (LCDs). Since the design concepts are different for 2D/3D and 3D/2D displays, the switching characteristic of BLU with two confronting illuminating sets, was applied to build 2D mode into 3D display, and 3D mode into 2D display. A design based on the 2D concept required a uniform bilateral prismatic structure with a cross-section of isosceles triangle on the back surface of the functional light-guide plate (LGP). This structure led to an increase in double-sided uniformity, i.e., for double-sided illuminations (2D as primary function of the 2D/3D display), and a decrease in single-sided uniformity, i.e. for single-sided illumination. However, a design that was based on the 3D concept required an angle gradation for the unilateral prisms with a cross-section of a scalene triangle on the back surface of the functional LGP that led to an increase in single-sided uniformity and a decrease in double-sided uniformity (3D as primary function of the 3D/2D display). Both switching concepts were used to display 3D and 2D on the LCDs of small size handheld game devices and still cameras.

Effect of high-frequency induction weld seam on the deformation of M1700 ultra-high strength steel shell structures considering residual tensile stress

The feasible cold forming procedure to massively manufacture ultra-high strength steel (UHSS) light-weighting profiles so far in industrial fields consists of roll forming, welding, cutting and bending. To reveal the role the high-frequency induction weld (HFIW) line plays in the subsequent plastic forming, a serials of deliberately designed collapse tests of the shell structures taken from M1700 roof rail pillar with a wall-thickness of 2 mm and triangle cross-section were conducted. Real geometries and inhomogeneous material properties of the weld seam and heat-affected zone (HAZ), together with the residual tensile stresses within the weld seam after HFIW, were fully considered in the numerical simulation. The Brozoo's modified CL damage model and Oyane damage model were employed and compared. The results show that the deformation resistance of the shell structures is modified by the material accumulation around the HFIW seams during the collapse tests. The cracks mainly occur within the critical HAZ outside the tube and the temper softening zone inside the tube under the action of softening effect in the HAZ of M1700 steel. The residual tensile stresses increase the crack probability of weld seams. The predicting accuracy of fracture location of the Oyane damage model is higher than that of the Brozoo's modified CL damage model.

The CFD analysis of the effect of internal peak angle and mass-flow rates on the thermal performance of solar air heater with triangle cross-section

A new design of solar air heater with triangle cross-section is numerically studied. The thermal performance of solar air heater is studied at various mass-flow rates, inlet air temperatures, and solar irradiation intensities. The CFD model is developed using the software ANSYS FLUENT to study the fluid-flow and heat transfer in the solar air heater. The 3-D discretization is applied to study the thermal performance of solar collector with triangle cross-section. Mesh independence is performed in order to choose the adequate mesh. The discrete ordinate radiation model and the RNG k-? turbulence model are used to study the radiative heat transfer and the turbulent flow inside the solar air heater. Particularly, effects of different internal peak angles (145?,126?, 100?, 80?, and 67.5?) under different solar irradiation intensities (from 620-1081 W/m2) are studied to improve the thermal performance of the solar air heater. The results show a good agreement between the numerical model and the experimental data with an average error of 6%. The maximum outlet air temperature of the solar air heater reached 72 ?C for the geometries with 12 and 16 channels (internal peak angles of 80? and 67.5?, respectively) under mass-flow rate of 0.0264 kg/s. The thermal performances of the solar air heater with 16 and 12 channels are 24.2% higher than standard geometry, respectively for solar irradiation intensity of 1081 W/m2. The configuration with internal peak angle of 80? and 12 channels is selected as the optimal with a thermal efficiency of 79%, a low pressure drops compared to geometry with 16 channels and lower costs.

Comparison of vapor cooling characteristics of a triply periodic minimal surface and other channel geometries

Vapor cooling shield is a key technology for long-term cryogenic propellant storage in space. Cooling channels with a triply periodic minimal surface embedded inside are expected to improve its cooling performance. Herein, a cooling channel with a triangle cross-section embedded gyroid structure, a type of the triply periodic minimal surface structure, was additively manufactured. The pressure drop and heat transfer performances of the channel were experimentally measured using liquid nitrogen vapor. Furthermore, in addition to the gyroid-embedded channel, three channels with different cross-sections were fabricated for comparison: circular, triangle, and triangle with a step/groove on the bottom. The gyroid-embedded channel exhibited unique characteristics, with a thermal conductance that was approximately 40% higher than that of the channel with a simple triangle cross-section, but an excessive pressure drop of approximately 50 times higher than that of the other cross-sections. This denotes that strong vortex and turbulence and the flow separation cause excess pressure drop in the gyroidembedded channel. The pressure drop characteristic of the gyroid-embedded channel against the Reynolds number completely differed from that of the other channels, and the pressure drop of the gyroid-embedded channel can be estimated assuming analogy with particle packed beds.

Effects of Reynolds number on wind effects toward a super-tall building with curved cross-section

Wind resistance is of great importance for the safety and applicability of high-rise buildings, and wind tunnel tests are generally exploited to facilitate associated wind-resistant design. However, owing to the adoption of downscaled models, Reynolds-number (Re) effects on wind tunnel testing results may not be neglected especially for structures with circular or quasi-circular sections. Although great efforts have been made to explore the Re-effects, the range of Re concerned in most studies is too limited to cover that associated with the reality. This article investigates the Re-effects on various wind effects toward a super-tall building which is featured by a spatially varying curved cross-section, based on a comprehensive usage of wind tunnel test and field measurement. The dependence of Strouhal number, pressure, layer force, structural response and equivalent static wind load upon Re from 2.5 × 104 to 3.8 × 107 is analyzed and compared with their counterparts for triangle sections and circular cylinders. Results suggest typical wind effects of the building differ distinctly from those for a circular cylinder. Both the global geometric features of the cross section and its local details (in particular the blunt leading edges) may play a significant role in forming the flow structures around the building and therefore in resulting in corresponding wind effects. Basically, at portions where the cross section varies insignificantly with height, results are much similar to those for a triangle cross-section and are less sensitive to Re; while at portions where the cross section varies significantly with height, some results become dependent greatly upon Re. Overall, the structural responses of this building first increase and then tend to level off with the increase of Re, and wind tunnel testing results basically agree with field measurements when Re exceeds about 1.3 × 105.

Double-Cavity Modulation of Exciton Polaritons in CsPbBr3 Microwire.

The lead halide perovskite has become a promising candidate for the study of exciton polaritons due to their excellent optical properties. Here, both experimental and simulated results confirm the existence of two kinds of Fabry-Pérot microcavities in a single CsPbBr3 microwire with an isosceles right triangle cross section, and we experimentally demonstrate that confined photons in a straight and a folded Fabry-Pérot microcavity are strongly coupled with excitons to form exciton polaritons. Furthermore, we reveal the polarization characteristic and double-cavity modulation of exciton polaritons emission by polarization-resolved fluorescence spectroscopy. Our results not only prove that the modulation of exciton polaritons emission can occur in this simple double-cavity system but also provide a possibility to develop related polariton devices.

Aerodynamic noise characteristics of non-circular cylinders in subcritical flow regime

The present study experimentally investigates the aerodynamic noise from the flow around cylinders of square and equilateral triangle cross-sections at different angles of incidence ( α). The cylinder models have a side dimension of 10 mm and a span of 300 mm. The free stream velocity ( U 0) is in the range of 12–36 m/s, and the corresponding Reynolds numbers are 7.8 × 103 to 2.3 × 104, which is in the subcritical flow regime. The characteristic acoustic tones are generated at α = 30° and 45° for square and triangular cylinders. The frequency of acoustic tones linearly increases with the free stream velocity, and the corresponding Strouhal numbers are found to be in the range of 0.13–0.16. Depending on the angle of incidence, the overall sound pressure level is higher than the background noise by 4–24 dB for the square cylinder and 3–15 dB for the triangular cylinder at U 0 = 36 m/s. The highest noise level of the square cylinder is 90 dB at α = 45° and 79 dB at α = 30° for the triangular cylinder. The spectral scaling with the sixth power of the free stream velocity indicates the dipole behaviour of the acoustic tones. The mean and root-mean-square velocity profiles in the wake region characterise the noise emissions at different angles of incidence. The comparative acoustic study of the non-circular cylinders with a circular counterpart showed that the highest noise level is from the square cylinder at α = 45°. The directivity study shows that the noise level of the square cylinder at α = 45° at 90° angular location ( θ) is higher by 6.5 dB than that at θ = 30°.

On the meniscus shape and marangoni flow in capillary tubes with noncircular cross-section shapes

The liquid–vapor interface remains a key point for improving the heat transfer efficiency of heat exchangers. In this paper, we report experimental results on the evaporation of ethanol in capillary tubes of different internal cross-sections as the bulk meniscus recedes inside the tube, since the chosen conditions allow for the development of a liquid film along tube's internal corners due to the presence of capillary forces. To achieve our aims, we used 3D video microscopy to monitor the behavior of the meniscus during evaporation and, also, calculated the capillary pressures for three channels with different cross-sectional shapes each, namely circular, square and equilateral triangle cross-sections, for three solid–liquid contact angles, i.e., 30°, 60°, and 90°. At the same time, we have combined infrared thermal imaging technology with particle imaging velocimetry (PIV) visualization technology to analyze the severe Marangoni convection at the included angle. To this end, the interfacial temperature distribution of Marangoni convection was measured by means of an infrared camera and the flow pattern by means of PIV, respectively, through the plane in various views. For capillary tubes with included angle, the temperature gradient at the meniscus reaches its maximum at the included angle. Moreover, both temperature and convective gradients exist in the liquid film with included angle. When the angle of the capillary tube is smaller, the capillary effect will increase, leading to the formation of a thicker film. Our investigation constitutes an “extreme” experiment of Marangoni flow at the corners of the capillary tube. Due to the capillary forces, liquid films can rise in the corners of polygonal tubes up to the entrance of the tubes. Furthermore, the wetting force of ethanol at the angle of the triangle tube is much larger than that in the case of the square tube. Finally, the Marangoni vortex flows from the relatively high-temperature region in the center of the liquid towards the included angle, where evaporation is faster and the recharge of material and energy is more concentrated. We anticipate that our study sheds light into the meniscus shape and Marangoni flow in capillary tubes of with cross-sections of different shapes, which is of fundamental importance for various applications and in particular microfluidic systems.

Investigating anisotropic blast wave parameters near the explosive-air boundary using computer simulation and experimental techniques with varying charge geometry

The prediction of blast wave overpressure using scaled distance calculations use the charge mass and radial distance variables and assumes that the blast wave is isotropic. Simulations and empirical studies demonstrate that altering the charge geometry results in a significant deviation in overpressure vs orientation. While this effect has been measured for cylinders, truncated cones, and cubes, the mechanisms driving geometric blast wave product anisotropy have not been well defined. Velocity vectors plotted from computer simulations in this study show an isotropic radial flow from the cylindrical charges, while the prismatic charges with rectangle, triangle, and five-point star cross sections had significant anisotropy and are overdriven normal to the sides of the charge and underdriven at the corners. The radial expansion of the rim of the dent is measured at the corners and normal to the sides of the charges as an indicator of radial energy distribution and particle flow during breakout. The depth of the dents shows a linear relationship with the breakout radii of the charges with an R2 value of 0.99. The radial displacement of the dent rim from the perimeter of the explosive charge is uniformly 5.5 mm around the cylindrical charge but is up to 1.5 times than normal to the sides of the prismatic charges and zero at the outside corners indicating an energy flow from the detonation wave toward the initial breakout locations.

Imbibition of Newtonian Fluids in Paper-like Materials with the Infinitesimal Control Volume Method

Paper-based microfluidic devices are widely used in point-of-care testing applications. Imbibition study of paper porous media is important for fluid controlling, and then significant to the applications of paper-based microfluidic devices. Here we propose an analytical approach based on the infinitesimal control volume method to study the imbibition of Newtonian fluids in commonly used paper-like materials. Three common paper shapes (rectangular paper strips, fan-shaped and circular paper sheets) are investigated with three modeling methods (corresponding to equivalent tiny pores with circle, square and regular triangle cross section respectively). A model is derived for liquid imbibition in rectangular paper strips, and the control equations for liquid imbibition in fan-shaped and circular paper sheets are also derived. The model is verified by imbibition experiments done using the mixed cellulose ester filter paper and pure water. The relation of imbibition distance and time is similar to that of the Lucas−Washburn (L−W) model. In addition, a new porosity measurement method based on the imbibition in circular paper sheets is proposed and verified. Finally, the flow rates are investigated. This study can provide guidance for the design of different shapes of paper, and for better applications of paper-based microfluidic devices.

Characteristics of multi-mode lasing in cesium lead bromide perovskite microwires with an isosceles right triangle cross-section.

The CsPbBr3 microwires with unique isosceles right triangle cross-sections are commonly observed via chemical vapor deposition method. In this work, we study the correlations between measured multi-mode lasing behaviors and the simulation of the mode patterns inside the triangular-rod microcavity. We confirm that lasing action with higher-order transverse modes can well sustain, even when these modes experience large optical loss due to the isosceles triangle cross-section. By comparing the experimental and simulation results, the higher-order transverse modes tend to show up prior to the fundamental transverse modes for wider microwires. We attribute this behavior to the nonuniform field distribution caused by the high absorption efficiency of CsPbBr3. We also elaborate on the difficulties to sustain the whispering gallery mode in the CsPbBr3 triangular-rod microcavity, which implies that the lateral dimension and geometry of the cavity should be considered carefully for the future design of low threshold wire-based laser devices.

Impingement and freezing of a supercooled large droplet on an ice surface

In the present study, we carried out an experimental investigation of the impinging and freezing processes of a supercooled large water droplet on an ice surface. One high speed camera was used to measure the dynamic motions of the water droplet while two charge coupled device (CCD) cameras were adopted to obtain the images of the freezing process and the freezing morphologies, respectively. The effects of the water droplet temperature and the ice surface temperature on the impact and freezing processes of the water droplet were carefully evaluated. The results showed that the subcooling degree of the water droplet had an apparent influence not only on the spreading process but on the freezing morphology as well. When the subcooling temperature of the water droplet was high (e.g., Tw = –3.0 °C), a triangle cross-section profile formed. However, once the subcooling temperature of the water droplet was relatively low (e.g., Tw = –9.0 °C), the final ice morphology consisted of two parts: one part was a cone-like bead in the center while the other part was an ice ring at the periphery. Moreover, at the same water droplet temperature, raising the ice surface temperature led to an increase in the maximum spreading factor.

Mechanics of Magnetic Robots Akin to Soft Beams Supported at Unanchored Contacts

Abstract This article presents a novel algorithm to predict the shape and the support configurations of a magnetic robot acting like a supple beam, which deforms due to an imposed magnetic field. The soft magnet loosely rests on a flat horizontal surface, which provides the pivoting supports to the robot to attain its deformed shape. The key difficulty in analysis of the mechanics is the lack of any prior knowledge about the location of the contacts where the distorted beam finds support from the ground. This article outlines an algorithm in which different possibilities referred to as modes are checked systematically to locate the placement and the nature of such supports. Consequently, the 2D shape of the soft beam can be determined without any heuristic assumption about where the magnetic robot is touching the solid surface. This study focuses on single contact sections although the algorithm idea is valid for multiple contacts as well. The mathematical theory and the numerical scheme are validated by comparing the simulated results with existing experimentally obtained configurations. Also, the parametric space of system-defining nondimensional parameters is explored to determine when a transition happens from one mode to another and which magnetization methods are desirable for higher stability. Through theoretical simulation, the results show that a thin rectangular cross section provides higher deformation when compared to the other two tested shapes (circular and equilateral triangle cross section).

Trust-Region Based Penalty Barrier Algorithm for Constrained Nonlinear Programming Problems: An Application of Design of Minimum Cost Canal Sections

In this paper, a penalty method is used together with a barrier method to transform a constrained nonlinear programming problem into an unconstrained nonlinear programming problem. In the proposed approach, Newton’s method is applied to the barrier Karush–Kuhn–Tucker conditions. To ensure global convergence from any starting point, a trust-region globalization strategy is used. A global convergence theory of the penalty–barrier trust-region (PBTR) algorithm is studied under four standard assumptions. The PBTR has new features; it is simpler, has rapid convergerce, and is easy to implement. Numerical simulation was performed on some benchmark problems. The proposed algorithm was implemented to find the optimal design of a canal section for minimum water loss for a triangle cross-section application. The results are promising when compared with well-known algorithms.

Adaptive control system to producing a novel spun parts in sheet metal spinning process

The problem in Sheet metal spinning is limited to an axisymmetric part. This research aims to design and build a flexible mechanism by a combination of mechanical with the electrical system to achieve the forming of polygon spun parts with a different number of sides without using a specific mandrel. This system based on developing a synchronous spinning machine, in which the rotational motion and feeding of the tradition lathe machine were measured and control to maintain the speed synchronization with the trajectory of the forming tool rollers (a special tool of forming), where this tool controlled by the electrical motors. The speed of the electric motor controlled by variable frequency drives VFD, pulse-controlled, and software. The machine can be applied to produce several shapes by changing pulse-controlled inside software code, which means that’s the machine is much more flexible than any other way. In this survey three spun parts (triangle, square and hexagonal) cross-section parts were produced, and aluminum alloy sheets (1050) of circular shape with 1.5 mm in thickness and 150 mm diameter will be used in this process. Finally, the output from this process will compare with a CAD model to examine the process validity by comparing the dimensional accuracy. The result shows that the average dimensional accuracy error for the triangle, rectangular, and hexagonal spun parts are 14.15, 6.47, and 3.78 respectively which consider an acceptable percentage in the spinning process.

PEM fuel cell cathode-side flow field design optimization based on multi-criteria analysis of liquid-slug dynamics

Since the Gas Diffusion Layer (GDL) clearance and the residence time of produced water in gas channels remarkably affect the proper operation of proton exchange membrane (PEM) Fuel Cells, the water management in this part plays a key role. To this end, the present study aims to introduce novel and optimized gas channels through geometrical modifications that act efficiently in terms of GDL clearance and liquid residence time. For this purpose, the VOF (Volume of Fluid) model was employed to numerically simulate two-phase flow by means of a finite volume method. Several decisive parameters including superficial gas velocity, channel surface wettability, and channel cross-section geometry were considered to find their effects on the liquid removal behavior. The liquid removal performance was analyzed by two-phase pressure drop, area coverage ratio (ACR), and liquid removal time. Results have been compared with previous works done on the conventional rectangular channels. Interestingly, it was found out that for the analyzed segment of the gas flow channels, the channel with triangle cross-section has superior performance in reducing ACR by 64% for inlet superficial air velocity of 0.5 ms and 8–24.45% reduction for higher velocities (1, 1.5 and 2.5 ms). Also, the transition from slug flow to film flow also stable two-phase pressure drop were only seen in this type of channel. The ranking of channels based on their residence time merit is as: hexagon>pentagon>rectangular>triangle. Increment of the contact angle of hydrophilic walls causes fluctuations in the two-phase pressure drop and decreases liquid water residence time. For triangle channel, surface with a contact angle of ∼120° and for the hexagon and pentagon channels 85–120° is suggested for the best fuel cell performance.

Effect of transverse triangular wedges on the behavior of the ash deposition and heat transfer of an inline tube bundle

The experiment was carried out on an inline 6 rows – 3 columns tube bundle. Free air velocity and coal fly ash feed rate were kept constant at 2.1 ms−1 and 3.65×10−4kgs−1, respectively. The wedges have isosceles triangle cross section and have the same height. The investigation is carried out for four ratios of base to height or aspect ratio: 0.275, 0.550, 0.758 and 1. The wedges are installed transversely across the bundle cross section and parallel to the tubes at the tube bundle inlet, between the second row and the third row, between the fourth row and the fifth row, or at the tube bundle outlet. It is found that flow patterns of the single-phase air flow (SPF) over the tube bundle and the deposition patterns around the tube are related. The deposition coverage angles at the tube upstream start from the points having zero wall flow shear stress and where the flow is toward the surface and having zero wall flow shear stress and where the flow is outward from the surface for the first-row tube and the rest, respectively. For both cases, the ash continues to deposit on the surface to the point having maximum wall shear stress. The average rate of the increase in the shear stress over the coverage angle is an important parameter for predicting the deposition. The deposition decreases as the average rate over the upstream tube surface decreases. It decreases significantly at the adjacent tubes upstream and downstream of the wedges. Based on the deposition and the heat transfer, the optimum wedge position is in the vicinity of the middle length of the tube bundle. In addition, the deposition and the heat transfer decreases and increases with the wedge aspect ratio. In terms of the enhancement of the heat transfer for the same air pumping power, a wedge with an aspect ratio of 0.550 or 0.758 should be installed at the tube bundle inlet.

Effect of transverse triangular cross-sectional wedges on the asymptotic fouling deposition behavior of the flow through an inline tube bundle

The deposition on a superheater and economizer may come from loose ash particles adhering to their tube surfaces. It causes a fouling thermal resistance, an increase in the flow pressure drop, and hence a higher operating cost. An active approach such as using a high-grade fuel can diminish the effect. However, it is costly. The deposition may be predicted using sophisticated computational fluid dynamics software. Alternatively, for the asymptotic mode of deposition, it might be predicted by the lumped models proposed by various researchers. However, they can be used to predict only the saturated time and the overall saturated thermal resistance. In this work, a novel passive approach is proposed. Isosceles triangle cross section wedges were installed parallel to the tubes to increase the wall shear stress due to the flow (t) and hence decrease the deposition. In addition, by modeling the tube bundle as a lump, a mathematical formulation for predicting the deposition behavior of the tube bundle was developed. The experiment was carried out on an inline 6 rows – 3 columns tube bundle with constant air velocity and ash feed rate. Four isosceles triangular wedges with the same height but with different base (b) to height (e) ratio or aspect ratio (α), with α= 0.275, 0.550, 0.758 and 1 being used. Three wedge positions from the tube bundle inlet in the direction of the flow (x) to the tube bundle length (L) ratios (x/L) are considered: at the middle between the second row and the third row (x/L=1/3), at the middle between the fourth row and the fifth row (x/L=2/3), and at the tube bundle outlet (x/L=1). The regression approach was used to analyze the overall thermal resistance obtained from the experiment, according to the obtained mathematical relation. The saturated time and the overall saturated thermal resistance obtained from the analysis were used to calculate the deposition rate on the tubes (fd), the removal rate of the deposition, deposition growth rate, coefficient of the deposition (kd) and coefficient of the removal (kr). The result showed that the overall saturated thermal resistance and deposition were inversely proportional to t. fd, the removal rate, the deposition growth rate, kd and kr increase with the wedge distance. Except for fd and kd, those parameters were sensitive to a. The tube bundle with wedges has higher values for those parameters. For the bundle with wedges, those parameters were inversely proportional to t. The product of kr and t is the governing parameter of the saturated time.