V-shaped Ribs Research Articles

V-Spline Design for Enhanced Performance in Turbine Blade Internal Cooling

Abstract Past experiments have consistently shown that V-shaped rib turbulators are among the best in heat transfer performance. While there is literature on the V rib design in various experimental studies, there is no literature that shows the V rib design applied on any current turbine blades. Instead, the straight and angled rib design are used. The V rib only offers a marginally better heat transfer performance over the angled rib, but it has a severe stress concentration at the rib tip. In this research, multiple design augmentations were analyzed, with the addition of a spline at the center of the V exhibiting alleviation of the tip stress concentration. The results show that the presence of the spline not only resolves the fatigue issues but also increases the heat transfer performance by 4.3% and 8.2% against the V rib and angled rib design, respectively. With a better heat transfer performance, the creep analysis shows that the turbine blade with a V-spline rib design can operate at temperatures 203 °C hotter than an angled rib at the same fluid power. Given the dependence of engine thermal efficiency on turbine inlet temperature, this simple design shows good potential for heat transfer augmentation.

Optimization and evaluation of thermo-hydraulic performance of solar air heaters equipped with different roughness geometries

Solar air heaters have poor thermal efficiency. Applying artificial roughness elements is a common approach to enhance thermal performance of a solar air heater. In this study, fluid flow and heat transfer characteristics of solar air heaters equipped with six different roughness geometries, including inline cubical elements, staggered cubical elements, rectangular baffles, square ribs, V-shaped baffles, and V-shaped ribs, were assessed. First, parameters of each roughness geometry were optimized and then thermo-hydraulic performance of solar air heaters having optimum roughness geometries was compared. For each roughness geometry, two design parameters were selected and 25 numerical experiments were designed based on the full factorial design of experiment approach. The thermo-hydraulic performance parameter (THPP) was set out as the objective function and its relationship with roughness parameters was defined using the non-parametric regression response surface method. Finally, the optimum values of roughness parameters were determined using the nonlinear programming by quadratic Lagrangian (NPQL) technique. Comparing the performance of solar air heaters having optimum roughness geometries showed that rectangular baffles led to the largest and inline cubical elements brought about the smallest THPP at almost all Reynolds numbers. The maximum THPP of rectangular baffles was 2.28 at the Reynolds number of 25,000.

Development of correlations of Nusselt number and friction factor of solar thermal collector equipped with hybrid rib roughness

In this advanced and comprehensive research, a pioneering hybrid rib configuration, amalgamating arc and V-shaped ribs, is precisely engineered to delve into the complex synergistic effects between this cutting-edge rib design and the heat transfer and fluid flow behavior within a solar thermal collector (STC) specifically utilized for direct air heating. The focal point of this investigation is the impact of the rib pattern on pivotal performance indicators, notably the Nusselt number (Nu) and the friction factor (f). This specific rib roughness design emanates from an exhaustive analysis of a spectrum of non-dimensional roughness parameters: the arc angle (α), the attack angle (β), the relative positioning of the V ribs (D/w), the relative spacing of the ribs (p/e), and the rib height (e/D). These parameters are studied within defined ranges: 30̊‐60̊, 30̊‐60̊, 0.2–1, 8–12, and 0.023–0.043, respectively. The results of highlight a significant improvement in heat transport, as indicated by a significant increase in the Nusselt number (Nu), which has risen impressively by a factor of 3.08. Furthermore, this paper presents development of correlations for Nu and f, taking into account the roughness parameters of the hybrid ribs and the flow Reynolds number, in order to precisely forecast these key performance measurements.

Investigation of Heat Transfer Enhancement and Entropy Increment in a U Channel with V-shaped Ribs for Improved Hydrothermal Performance

Investigation of Heat Transfer Enhancement and Entropy Increment in a U Channel with V-shaped Ribs for Improved Hydrothermal Performance

Experimental and numerical investigation of jet impingement cooling onto a rib roughened concave internal passage for leading edge cooling of a gas turbine blade

Considered is thermal protection of the concave surface within an internal passage, which models the leading edge cavity of vanes or blades of stationary or aero engine gas turbines. Included along the internal surface are different arrangements of V-shaped ribs to further augment surface cooling heat transfer rates. Impingement jets are employed for the cooling, which are configured so that associated cooling air exits the cavity through a crossflow outlet and an array of staggered film cooling holes. The curved part of the asymmetric, concave target plate features a constant radius and connects to straight lines on the pressure and suction sides. Addressed are H/Djet values of 2.7 and 4.0, and Reynolds number Re values of 18,000, 24,000, and 30,000. A maximum crossflow configuration is utilized wherein the coolant flow exits the cooling passage through the film cooling holes and from one end of the passage, as the opposite end is blocked. Different surface configurations are investigated, including 4 V-ribs in four different positions, 8 V-ribs in one position, and a smooth surface of the leading edge cavity. Each V-rib geometry consists of a regular V-rib pointing upstream. A transient thermochromic liquid crystal (TLC) technique is employed to obtain spatially-resolved surface heat transfer data on the internal wall of the leading edge cavity. Resulting experimental heat transfer data are used to validate and verify CFD simulations. Employed for this purpose are steady-state 3D RANS simulations obtained using the OpenFOAM Version 7 numerical code with a kω-shear-stress-transport (SST) turbulence model. Experimentally-measured surface Nusselt number results indicate significant local enhancements adjacent to rib wakes, provided local crossflow velocity values are substantial. Local surface Nusselt number enhancements thus depend upon rib position, but local surface heat transfer increases are most strongly tied to magnitudes of local crossflow velocity. In contrast to these experimental results, CFD simulation results do not show significant variations as rib position is altered. The best thermal performance is associated with 4 V-rib arrangements in two positions, and 8 V-ribs in one position.

Thermal performance augmentation in a pipe employing hybrid nanofluid and a plate as turbulator with V-shaped double-winglet ribs

This article employs a plate with V-shape ribs inside a tube as turbulator to augment the heat transfer rate. The utilized vortex generators are double-winglets arranged in a V-shape placed on both sides of the plate. The proposed system’s suggested working fluids are water-based hybrid nanofluids, including Al2O3–Cu/water, Cu–CuO/water, and Cu–TiO2/water. This work involves a numerical evaluation of the effects of the type and volume concentration of the examined hybrid nanofluids on the enhancement of heat transfer. The experimental results are used to validate the numerical model. It is worth mentioning that all the obtained numerical results are compared with the simple tube, without any turbulator (vortex generator) and in the presence of water instead of the hybrid nanofluids. Based on the numerical results, it can be concluded that all employed hybrid nanofluids showed improved thermal performance compared to pure water. Furthermore, the differences between the models are more substantial for higher Reynolds numbers than for lower Reynolds numbers. In Re = 30,000, the Cu–TiO2/water exhibits the lowest thermal performance improvement (augmentation of about 0.3%), while the Cu–CuO/water at Re = 50,000 exhibits the largest thermal performance improvement (augmentation of approximately 5.7%), in the case of ∅1 = ∅2 = 0.5%. For ∅1 = ∅2 = 1%, the Cu–TiO2/water at Re = 30,000 has the lowest thermal performance improvement (augmentation of around 1.1%), while the Cu–CuO/water at Re = 50,000 has the most thermal performance improvement (augmentation of roughly 8.7%). According to the augmentation of around 2.8% at Re = 30,000 for Cu–TiO2/water and approximately 10.8% at Re = 50,000 for Cu–CuO/water, the thermal performance increase in the scenario of ∅1 = ∅2 = 1.5% is the lowest. In Conclusion, the Cu–CuO/water hybrid nanofluid with a volume concentration of ∅1 = ∅2 = 1.5% has the greatest thermal performance value of all the hybrid nanofluids studied.

Numerical analysis of jet impingement cooling with elongated nozzle holes on a curved surface roughened with V-shaped ribs

Numerical studies were performed in this study to analyze the effect of dimensionless elongated injection holes (G/d = 0.5, 2.0, 4.0, 8.0) on heat and flow characteristics on rib-roughened surfaces with an array of inclined impingement jets. Experimental and numerical data from existing literature were used to validate the numerical solution procedure’s heat transfer and flow characteristics in the semicircular test section. The turbulence equations were solved using the SST k-ω turbulence model by varying the Reynolds number from 5000 to 25,000. The curvature effect and staggered array pattern created an additional stagnation region between adjacent impinging jets on smooth surfaces, leading to a low heat transfer zone. Rectangular cross-sectional V-shaped ribs (VSR) were placed in regions where the stagnation point occurs to eliminate this disadvantage. The effect of different normalized rib heights (Hr/d = 0, 0.2, 0.3, 0.4) and rib angles (α = 30°, 45°, 60°, 90°) on the curved surface was also investigated to increase convective heat transfer performance and achieve more homogenous heat transfer distribution by relatively reducing the effect of thermal stresses. Flow properties, area-averaged and local Nusselt number variations on smooth and ribbed surfaces, and the thermal performance criterion (TPC) were investigated in detail. The results indicated an increase in overall heat transfer and a more evenly distributed measurement region compared to the conventional (unextended jet and smooth surface) jet impingement configuration. The most significant heat transfer enhancement from combining the elongated jets with VSR was 47.23% at Hr/d = 0.2 by reducing the G/d to 0.5. In addition, the highest TPC was determined as 1.07 on the proposed model with G/d = 2.0 and Hr/d = 0.2 at Re = 25,000.

Thermal performance analysis of triangular solar air heater duct having broken V-shaped ribs

In the present investigation, a numerical study has been done to analyse the effect of attachment of broken V-shaped ribs on the heating surface of the triangular-shaped solar air heater duct. The roughness and flow parameters include relative roughness pitch (between 8 and 14), angle of attack (between 30 and 75 degrees) and Reynolds number (between 4000 and 20,000). The effect on heat transfer and flow characteristics has been observed due to variation in parameters. Considerable enhancement in convective heat transfer is observed along with frictional effect and indicated by Nusselt number and friction factor values. All the variations resulted in an increase in the performance of a solar air heater, which was indicated by the value of the thermohydraulic performance parameter being more than 1. Abbreviations: CFD, Computational fluid dynamics; SAH, Solar air heater; THPP, Thermohydraulic performance parameter

Impact of V-shaped interrupted ribs in cross-flow channels on film cooling

This study primarily investigates the enhanced heat transfer of V-shaped ribs with?in an internal cross-flow channel and their impact on external film cooling per?formance. The aim is to assess the advantages of V-shaped ribs in the cooling of gas turbine blades. The research specifically discusses the internal heat transfer efficiency of smooth channels, channels with V-shaped ribs, and channels with intermittently placed V-shaped ribs at a blowing ratio, M, of 0.5 and three different Reynolds numbers. The results indicate that the vortices generated by the coolant passing through the positive V-shaped ribs and intermittently placed V-shaped ribs effectively impinge on the upper and lower surfaces, thereby enhancing heat trans?fer performance. Regarding film cooling, under low Reynolds number conditions, the film cooling efficiency of the positive V-shaped ribs is 9-20% higher than that of the smooth channel. Under high Reynolds number conditions, the film cooling efficiency of the negative V-shaped ribs significantly increases, reaching 29-120%. The study demonstrates that rib shape and inlet Reynolds number have a signifi?cant impact on the swirl intensity of the coolant in the film cooling holes, and fluid with a certain swirl intensity exhibits better film cooling efficiency.

Multi-objective optimization of liquid cold plate with v-shaped ribs for lithium-ion batterys

The performance of lithium-ion batteries is affected by the operational temperature significantly for the NEVs, and should be below 338 K and 5 K, respectively in the actual project. An efficient thermal management system is essential for the battery, as it would ensure the safe operation and increase the battery life. In this study, the LCP with V-shaped ribs is applied to improve the heat transfer characteristics for guaranteeing the safe operational temperature of the battery. Based on the battery thermal models, the accuracy of numerical simulation through classical experimental correlation is verified, and is adopted to investigate the effects of different design factors on the heat dissipation of the battery, including the ribbed shaped, the distance between adjacent ribs and the inlet velocity of the coolant. The maximum temperature and the temperature difference of the battery and the pressure drop of the channel are taken as the design objectives. An orthogonal test and an entropy weighted-TOPSIS method are used to optimize the results with multi-objective analysis, then the optimal case of design parameters is obtained. The optimal case for the LCP is the ribbed shape of Model 2, the distance between the adjacent ribs of 30 mm and the inlet velocity of 0.3 m/s. A good balance is achieved between the heat dissipation of the battery pack and the pressure drop of the channel. The optimal case can reduce the maximum temperature and the temperature difference of the battery by 7.41K and 4.94K compared with the unoptimized cases, meanwhile the pressure drop is also effectively controlled.

A novel concept for a rib turbulator for optimizing the cooling performance in a square channel

In gas turbine operations, realizing the appropriate cooling of blades and vanes is crucial for ensuring long-term durability and high thermal efficiency. Internal convective cooling is widely used to direct coolant through a channel comprising rib turbulators to enhance the effectiveness of the cooling process. In this study, a numerical simulation is conducted to evaluate the effects of novel rib turbulator configurations under mist/steam two-phase conditions, specifically in relation to secondary flow and heat transfer characteristics. The morphologies of the secondary flow distribution and mist droplet trajectories induced by different rib turbulator configurations are carefully evaluated to elucidate the underlying mechanism of the heat transfer enhancement. Thus, the findings indicate that the configuration of the rib turbulator significantly affects the secondary flow distribution. In the novel concepts of discrete v-shaped rib turbulators with a single break and those with a double break, a notable increase in the longitudinal secondary flow was observed with a higher turbulence intensity. Moreover, such secondary flow compels mist droplets to accumulate and assemble at various locations within the channel. Subsequently, the heat transfer enhancement was localized in areas where the mist droplets accumulated in significant quantities. In terms of the optimization of the rib turbulator configuration, the adoption of a v-shape with a single break and discrete channel resulted in an enhancement of the Nusselt number by 45.07 % and the thermal performance factor by 88.57 %.

Performance improvement of solar air heater duct-employing rib roughness on absorber: an experimental study

ABSTRACT Solar energy is a pure and plentiful source of power for daily activities. Out of many solar thermal system, Solar air heaters (SAHs) are frequently regarded as the most economical and practical method of heating and drying indoor spaces. Due to its poor performance and minimal heat transfer capacity, its applicability in certain circumstances is quite limited. In this paper, an effort has been made to improve the heat transfer efficiency of SAH by utilizing hybrid ribs. Hybrid rib roughnesses are designed to integrate V-shaped ribs downstream of arc-shaped ribs and were experimentally tested in the SAH duct at Reynolds numbers (RN) between 2000 and 16,000. The various roughness pattern i.e. arc angle (α), relative V ribs position (d/w), relative rib pitch (p/e) and relative rib height (e/Dh) have been exploited in the range of 30º-75º, 0.2–0.8, 8–14 and 0.036–0.056, respectively. As a result, maximum enhancement in NuNu has been found as 3.75 at α = 45º, d/w = 0.5, p/e = 12, e/D = 0.056. Thermohydraulic Performance (TP) parameters have also been evaluated for all set of parameters and it was found to be maximum 2.49 at α = 45º, d/w = 0.5, p/e = 12, and e/Dh = 0.036.

Experimental investigation on jet impingement heat transfer analysis in a channel flow embedded with V-shaped patterned surface

ABSTRACT Heating and cooling systems benefit from jet impingement as it increases efficiency while reducing operating costs. The combined methodology, integrating jet impingement and passive heat transfer through the use of roughened surfaces, offers significant potential for improving heat transfer. This research presents the results of an experimental study on a channel flow commonly used for air heating, known as a solar air heater (SAH), with impinging air on the heated surface. The surface is embedded with V-shaped ribs as turbulence promoters, and it receives a continuous heat flow of 1,000 W/m2. Various design combinations were tested experimentally, including streamwise pitch ratio X/Dh = 0.866, spanwise pitch ratio Y/Dh = 0.866, jet diameter to hydraulic diameter ratio Dj/Dh = 0.065, and an angle of attack (α) ranging from 45° to 90°. During these experiments, the Re varied from 3,500 to 18,000. The optimal improvement was observed at values of X/Dh = Y/Dh = 0.866, Dj/Dh = 0.065, and α = 60°. This paper presents novel findings demonstrating that incorporating V-shaped rib patterns in SAHs can yield Nusselt numbers up to 5.2 times higher than those in smooth duct SAHs, offering substantial potential for enhanced energy efficiency. When the entering jet impacts and flows along the ribs of the absorber, the findings suggest that the V-shaped ribs accelerate the flow, resulting in enhanced heat transfer. All datasets were also analyzed for their thermo-hydraulic performance, with the maximum value recorded as 3.301 within the constraint range used in this analysis.

Experimental Validation of a Numerical Coupling Environment Applying FEM and CFD

Experimental results for the transient heat transfer characteristics over a flat plate and over a plate with V-shaped ribs were compared to numerical results from a coupling environment applying FEM and CFD. In order to simulate transient effects in the cooling process of engine components during typical flight missions, the temperature and the velocity at the inlet of the channel were varied over time. The transient temperature distribution at the plate was measured using infrared thermography. Five different plate materials (perspex, PEEK, quartz, aluminum, and steel) were considered to investigate the influence of thermal conduction on the heat transfer between solid and fluid depending on the Biot number. The experimental results represent a reference database for a Python-based coupling environment applying CalculiX (FEM) and ANSYS CFX (CFD). The results were additionally compared to numerical results simulating the complete transient conjugated heat transfer with CFD. A good agreement between the numerical and the experimental results was achieved using different coupling sizes at different Biot numbers for the flat plate and the plate with V-shaped ribs.

Enhanced heat dissipation of ribbed channels based on the coupling optimization of multiple structural parameters

The heat dissipation of ribbed channels is dominant by the strong coupling of multiple structural parameters, while it is less concerned due to the lack of efficient methodology both in experimental and numerical solutions. In the present work, the movable experimental facility and the CFD solutions based on the conjugate gradient method are established. Firstly, the coupling impacts of different parameters on the airflow field in the channel are identified. It is found that the longitudinal vortices coupling with transverse secondary flows are in charge of the heat dissipation of the ribbed channel. And the longitudinal vortices are affected by the relative roughness spacing, and the transverse secondary flow is mainly dependent on the aspect ratio for L-shaped rib, while for the V-shaped and W-shaped ribs, the transverse secondary flow mainly is mainly dependent on the angle of attack. Secondly, the coupling optimization of different ribs is completed and the optimal structural parameters are obtained using the developed experimental and numerical methodology. Overall, compared with the smooth channel, the optimal L, V and W-shaped ribs deliver the Nusselt number increasing by 83.04%, 155.18% and 197.17%.

A comprehensive numerical study on the fluid flow, thermal and exergetic performance of longitudinally ribbed spirally coiled tube with various shapes

The primary objective of this investigation is to examine the impact of rib configuration on flow behavior and heat transfer characteristics in a spiral tube with longitudinal ribs, through numerical simulations. Different cross-sectional shapes, including semicircular, V-shaped, trapezoidal, and rectangular ribs, are analyzed to assess the fluid flow, heat transfer, and exergetic efficiency of the tube. The findings indicate that incorporating longitudinal ribs of different cross-sectional forms substantially improves the fluid flow and thermal efficiency of the spirally coiled tube. An increase in rib depth leads to an accompanying rise in the Nusselt number, with improvements ranging from 18.4% to 27.9% for V-shaped and trapezoidal ribs, respectively. The spiral tube with rectangular shaped ribs exhibits the highest Nusselt number. Additionally, when the rib depth increases from 0.02 to 0.12 for the spiral tube with rectangular-shaped ribs, the THPP (Thermohydraulic performance parameter) experiences a significant increase of 38.1%. Also, the number of ribs (Nr) in the longitudinally ribbed spirally coiled tube has a crucial impact on its performance. Increasing the number of ribs results in higher heat transfer coefficients and Nusselt numbers for all tested rib shapes. However, the inclusion of more ribs leads to increased exergy destruction across all scenarios.

Performance evaluation with turbulent flow and heat transfer characteristics in rectangular cooling channels with various novel hierarchical rib schemes

Turbulators, such as ribs, dimples, and pin-fins, play a vital role in the internal cooling efficiency of turbine blades. As a typical turbulator, various rib configurations using a uniform arrangement scheme have indicated high heat transfer enhancement but the friction loss is simultaneously subject to a great increase. In this work, a novel hierarchical arrangement scheme of ribs is developed aiming to improve the cooling efficiency. Adopting the uniform scheme as a baseline, the hierarchical scheme is implemented for six representative rib configurations (including transverse ribs, angled ribs, V-shaped ribs, inverted V-shaped ribs, M-shaped ribs, and inverted M-shaped ribs) and evaluated for its feasibility and generality. For different cooling designs, turbulent flow and heat transfer of the ribbed cooling channel are studied by three-dimensional numerical simulations based on the finite volume method with a constructed turbulence model. It is found that for all rib configurations, the hierarchical scheme can remarkably reduce the friction loss as desired, especially for the inverted V-shaped rib with a reduction of up to 50%. Due to the occurrence of flow separation, secondary flows offered by transverse ribs are characterized by a two-dimensional recirculation vortex behind the rib. For other rib configurations, secondary flows present a typical three-dimensional characteristic including the downwash flows along the inclined rib leg and the longitudinal vortices. The usage of the hierarchical scheme with small ribs strongly suppresses these secondary flows, which contributes to the significant decrease in form drag loss. Meanwhile, using the hierarchical scheme produces a slight heat transfer deterioration commonly, which is because the constrained secondary vortices weaken the turbulent mixing and convection heat transfer. Significantly, for the two W-shaped ribs, the limited secondary vortices but fully developed under the hierarchical scheme achieve a higher heat transfer enhancement. Finally, for all considered ribs, the hierarchical scheme can improve the overall performance factor of (Nu/Nu0)/(f/f0)1/3 by more than 10%, and up to 21.15% for the V-shaped rib. Adjusting design variables, including the decreasing ratio of the rib size and the initial rib size, the hierarchical scheme still provides even higher performance enhancement.

Enhancing the performance of a solar air heater by employing the broken V-shaped ribs.

This work aims to enhance the performance of a solar air heater (SAH) by introducing broken V-ribs as roughness elements on the absorber plate. The unit with a conventional flat absorber plate is referred to as the "FSAH," while the unit with a broken V-rib-shaped absorber plate is called the "VSAH." The experiment was performed for three air velocities: 25 m/s, 20 m/s, and 15 m/s and the corresponding air flow rates were 0.037 kg/s, 0.031 kg/s, and 0.023 kg/s, respectively. The results showed that the maximum temperature was experienced on the absorber plate, followed by the glass plate for both SAHs. Overall, the average absorber and glass plate temperatures of the VSAH were 0.6-1.4 °C and 0.4-1.9 °C lower than those of the FSAH. Compared to the FSAH, the experimental results showed that the VSAH experienced useful power and thermal efficiency that were 16.6-19.8% and 15.7-20.4% higher, respectively, while the top surface heat losses were found to decrease by 2.1-8.1%. Due to the disrupted air paths in the VSAH, the observed pressure drop was 113.3-133.3% higher than that of the FSAH. More impotently, the thermo-hydraulic performance factor was always higher 1 and the observed values were 1.48, 1.39, and 1.24 at the va (velocity)values of 15, 20, and 25 m/s, respectively. Therefore, the proposed VSAH had an admirable thermal performance as compared to FSAH. Further, optimization through varying the roughness parameters, namely, relative blockage width (W/w), relative pitch ratio (P/e), number of baffles (n), relative blockage height (e/H), and angle of attack (β) could helped to achieve better performance.

Direct Numerical Simulation of Thermal Turbulent Boundary Layer Flow over Multiple V-Shaped Ribs at Different Angles

Direct numerical simulations (DNSs) of spatially developing thermal turbulent boundary layers over angle-ribbed walls were performed. Four rib angles (γ=90°,60°,45° and 30°) were examined. It was found that the 45° ribs produced the highest drag coefficient, whereas the 30° ribs most improved the Stanton number. In comparison to the transverse rib case, streamwise velocity and dimensionless temperature in the V-shaped cases significantly increased in the near wall region and were attenuated by secondary flows further away from the ribs, which suggested a break of the outer-layer similarity in the scenario presented. The surprising improvement of heat transfer performance in the 30° rib case was mainly due to its large dispersive heat flux, while dispersive stress reached its peak value in the 45° case, emphasizing the dissimilarity in transporting momentum and heat by turbulence over a ribbed surface. Additionally, by calculating the global and local Reynolds analogy factors, we concluded that the enhancement in heat transfer efficiency was attributed to an increasing Reynolds analogy factor in the intermediate region as the rib angle decreased.

Experimental Assessment of Thermohydraulic Performance of a Rectangular Solar Air Heater Duct Using Twisted V-Shaped Staggered Ribs

AbstractThe present experimental effort aims to determine the thermohydraulic performance of a rectangular solar air heater duct with V-shaped ribs staggered over the absorber plate. The performance test is conducted with variable roughness constraints, including relative roughness pitch (P/e) values between 7 and 11, relative staggered distance (d/e) values between 2 and 6, and relative arm length of twisted V-rib (S/e) values between 4.39 and 10.26, and flow Reynolds number values between 3000 and 21,000. The method of liquid crystal thermography is used to observe the dispersion of the Nusselt number over the roughened absorber surface. The maximum Nusselt number and friction factor enhancement ratio for roughened surfaces is determined to be 3.43 and 2.57 times that of a smooth plate, respectively. The parameters of rib configurations are adjusted based on the achieving greatest thermohydraulic performance (THP) index, which corresponds to P/e of 9, d/e of 4, and S/e of 6.15, yielding an optimum thermohydraulic performance measure of 2.69.