Triangular Ribs Research Articles

Inverse simulation to optimize the rib-profile in a rectangular flow-channel

Abstract An inverse optimization is performed for the shape (profile) of a rib-element that is located within a rectangular flow-channel. The optimization is useful to improve not only heat transfer but also to reduce the pressure drop of the channel. A simplified conjugate-gradient method and a multi-objective collaborative optimization method were used to find a profile inversion simulation model, where the shape is constantly updated until the performance evaluation factor reaches a maximum. It is found that inversion-optimization can effectively improve the overall performance of the system when the area of a rib base is given. For different heights and different shapes, the simulation always produces the same optimal solution. Furthermore, when the number of points reaches a certain number, the shape does not change nearly. One specific profile, which is obtained for Re = 8000, performs always better than the triangular rib surface, even though it does not represent the ideal shape for all cases. Finally, an additional optimization is carried out for different Reynold numbers. For the final optimized geometry, as the Reynold number increases from 3000 to 30,000, the objective function increases from 1.942% to 11.79%.

Thermal performance of a double-pass solar air heater (SAH) with ribbed absorber surface – an experimental study

PurposeUse of packed beds, enhanced tubes, nano-fluids and artificial ribs are few passive techniques to increase heat transfer in solar air heaters (SAHs). Artificial ribs attached to the absorber plate of the SAH will enhance the turbulence near the plate. Experimental analyses are conducted to find the thermal performance of SAH with ribs of regular geometries including rectangular, semi-circular and triangular in cross section. This paper aims to present the improvement in thermal performance of SAH with modified-arc.Design/methodology/approachAbsorber plates are designed with ribs of rectangular, triangular, semi-circular and modified-arc in cross-section using existing data in literature. Physical dimensions of the ribs are designed by adapting procedure from literature. Absorber plates are manufactured with ribs and coated with blackboard paint and fixed to the existing SAH. Experiments are conducted with a variable-speed blower fixed to the inlet section of the SAH, which is used to supply air at different mass flow rates in a range between 0.495 and 0.557 kg/min.FindingsEfficiency is found to be a strong function of mass flow rate of air through the SAH from the present experimental investigations. It was found that use of modified-arc ribs enhanced the efficiency of SAH by 105.35 per cent compared to SAH with plane absorber plate. Efficiency of SAH with modified-arc ribs is found to be higher by 24.43, 45.61 and 63.21 per cent, respectively, for SAH with semi-circular, rectangular and triangular arc ribs on its absorber plate.Research limitations/implicationsExperiments on SAH are conducted during daytime from 9:00 am to 5:00 pm in open atmospheric conditions. Solar intensity is continuously changing during the experimentation from morning to evening. Calculations are made based on the observations with average values of solar intensity and temperature readings. More accurate values of SAH efficiency can be obtained with constant heat supply to the absorber plate by simulating the experimental setup in indoor conditions. Temperature and flow rate observations could be more accurate with sophisticated instrumentation rather than using simple thermocouples and orifice meters.Social implicationsSAHs are basically used to supply hot air for both rural and industrial applications. These are used for crop drying, preheating of air, removal of moisture from leather, chemicals, etc. Conventionally, formers in India are using open sun drying to remove moisture from agricultural products. In this method, the moisture can be removed up to a level of 20 to 25 per cent. Use of SAH can remove moisture up to below 5 per cent and process is clean without reducing the quality of agricultural products. Enhancing the efficiency of SAHs will surely increase its usage by formers for crop drying.Originality/valueUse of artificial ribs on absorber plate of SAH is most economical among many of the active and passive techniques. Numerical and experimental investigations are found in literature with regular cross-sectional ribs, including rectangular, triangular and semi-circular. The present work proposed new shape of the ribs named as modified-arc, which was not presented in the literature. Experimental analysis proved that the use of modified-arc makes the SAH more efficient in heat transfer.

Experimental and Numerical Studies of Two-Phase Flow in Ribbed Periodic Vertical Channel

Pressure drop in a ribbed vertical channel was studied for a two-phase (air and water) flow, different shapes of ribs (triangle, semi-circular, and rectangle) were used in this investigation. An experimental rig was constructed with a test channel having the dimensions (10×3×70 cm) that enabled the flow patterns visual observation. An experimental setup of a two-phase was done for the present investigation, as well as a sum of (150) two-phase data with various flow patterns was determined. The used water superficial inlet velocities were in the range (0.0333 - 0.0888 m/s), and the air superficial inlet velocities were in the range (0.0555 - 0.1666 m/s). The experimental pressure drop according to a smooth plate was (41%, 38%, and 35%) for a channel fitted with semi-circle, rectangular and triangular ribs, respectively. The less pressure drop recorded was in the triangular ribbed channel, which indicates that the triangular shaped ribbed channel is the finest shape among the studied ones to lower the pressure drop. As future work, the numbers and dimensions of ribs can be changed to investigate its effect on the two-phase flow and the pressure drop, another suggestion for the future investigations is to include other fluid to have a three-phase flow, also the inclination angle of the duct can be changed to study its effect.

Identifying improved microchannel configuration with triangular cavities and different rib structures through evaluation of thermal performance and entropy generation number

Exploration of newer geometrical structures for microsinks stems from the desire to achieve better cooling at a lower pressure drop for more compact electronic devices. In this study, a three-dimensional conjugate heat transfer analysis is performed for a novel microchannel heat sink (MCHS) with disruptive structures in an otherwise rectangular channel. Each of these structural units has a pair of triangular cavities (TCs) on the opposite side walls and one in between the rib positioned symmetrically about the vertical mid-plane. Different units with diamond rib, rectangular rib (RR), backward triangular rib (BTR), and forward triangular rib (FTR) are analyzed. A notable finding of this work is identifying a rib as a disruption leading to thinning of the boundary layer on the side walls in the channel behind the rib. Another important contribution of a rib in both TC-RR and TC-BTR units is shown to promote chaotic advection due to having a longitudinal downstream vortex in each quadrant. The benefit of the lowest wall temperature is evident from the predicted results. Simple thermodynamic models are developed to establish that the minimization of entropy generation number (EGN) leads to the lowest temperature of the channel material for removing a given heat flux by the MCHS, and the maximization of the thermal performance (TP) implies achievement of the lowest pumping power. The corresponding numerical results are exploited for identifying the geometrical parameters over Reynolds number ranging from 197 to 595 that maximize the TP and closely minimize the EGN. The TC-FTR configuration is seen to yield the highest TP of about 1.78 at an intermediate value of Re around 400 along with low EGN of nearly 0.45. Results show that a microchannel with TC-BTR combination yields the highest heat transfer rate with a maximum pressure drop penalty leading to its poor TP. Thus, TC-RR turns out to be the choice in case a low wall temperature happens to be a critical requirement. A small sacrifice in it makes TC-FTR the choice for having the highest TP leading to a compact design.

Impact of heated triangular ribs on hydrodynamic forces in a rectangular domain with heated elliptic cylinder: Finite element analysis

Abstract The heat transfer in flowing liquid stream towards confined geometries having natural or man-made obstacles offers complex mathematical constraints at the heated body-liquid stream interface. Therefore, to appraise the heat transfer in liquid stream with installed obstacles particularly in terms of hydrodynamic forces remains a topic of great interest for the researchers. Owing such interest, the present article contains the extended evaluation of hydrodynamic forces in a flowing liquid stream with heat transfer individualities. To be more, the Newtonian liquid stream is initiated with the parabolic velocity profile at an inlet of partially heated rectangular channel. The heated elliptic shaped cylinder is placed fixed in between channel as an obstacle. The heated triangular ribs are installed case-wise namely (i) channel without ribs (ii) heated triangular rib at lower wall (iii) heated triangular rib at upper wall (iv) heated triangular rib at both upper and lower walls. The presence of heated triangular ribs as an obstacles modifies the endpoint conditions and hence the developed flow narrating differential system cannot be solved exactly. Therefore, the most trustful numerical method named finite element method with LBB-stable finite element pair is utilized to report acceptable solution in terms of streamlines and isotherms contour plots. The hydrodynamic forces are evaluated for each case by adopting line integration around outer surface of heated elliptic obstacle. It is noticed that when the heated triangular rib is installed on both upper and lower channel walls, the drag coefficient is found considerably high.

Numerical Study of the Boundary Layer Separation Control on the NACA 0012 Airfoil using Triangular Rib

This study includes a numerical simulation to investigate the aerodynamic behavior of the air flow around the surface of the NACA0012 airfoil, with and without a triangular rib. The triangular rib was used on the upper surface of the airfoil with size of 2% of the total chord length and variously located at 50, 70 and 90 percent of the chord length from the leading edge, separately as a passive control technique. Workbench-Fluent 17.2 version software was used to simulate the flow at 7 m/s freestream velocity (Re = 78,000), various attack angles (0˚ to 22˚) and chord length of 168 mm. The results indicated the presence of the triangular rib on the airfoil’s upper surface, at low angles of attack (less than 12˚), was a negative for the lift and drag results, at the angle of 12˚ it was a positive only for the location of 90%, while at the higher angles it was a positive for all locations and for all results where the lift increased and drag decreased. Therefore, the NACA0012 airfoil’s performance (lift to drag ratio) was significantly enhanced but, at 22˚, it had a very small effect for all results. It was concluded that the rib’s presence at 50% location delayed the stall angle by two degrees (from 14˚ to 16˚).

Geometric Optimization of a Gas Turbine Blade Cooling Passage using CFD

This work focuses on the rib-turbulated cooling which is a category of impingement cooling and aims at optimizing the geometry of rib-roughened cooling passage of a gas turbine blade. CFD analysis is carried out using Ansys/Fluent to solve the steady RANS equations. Computational domain consists of a long rectangular channel with the length of the channel being 9 times its height. Ratios of rib width, rib height and rib pitch to hydraulic diameter of the channel are taken as 0.1, 0.1 and 1.2, respectively. Numerical simulations are performed to analyze the performance of various rib shapes for Reynolds number, based upon the hydraulic diameter, in a range of 5000 to 50,000. Uniform heat flux of 800 W/m2 is applied to the ribbed wall. Incompressible air is used as the cooling fluid. Turbulent flow conditions are applied to the channel geometry with k-ω turbulence model. The effect of rib cross-section and rib pitch to rib width ratio on the heat transfer and friction factor is observed. The 2D CFD analysis revealed that the presence of ribs has significant effect on thermo-hydraulic performance of the cooling channel. Introducing square ribs in a smooth channel caused the Nusselt number to increase by two-folds. The highest value of Nusselt number was achieved by incorporating right-angle triangular ribs which caused the Nusselt number to increase by further 8%, as compared to the square ribs, and an increase in friction factor of 2.5%. The lowest value of friction factor was observed in semicircular ribs (2.95% less than the square ribs), however, the Nusselt number also decreased by 1.5%, as compared to square ribs. Decreasing rib pitch to rib width ratio increased both the Nusselt number and friction factor for all the cases. For square ribs, decreasing this ratio from 15 to 9 resulted in the rise of Nusselt number by 50% and increase in friction factor by 54%.

Forced convection heat transfer of water/FMWCNT nanofluid in a microchannel with triangular ribs

In this study, forced convection heat transfer of water/FMWCNT nanofluid is studied inside a rectangular microchannel with triangular ribs on the lower wall numerically. The nanofluid flow is affected by a uniform magnetic field. The ribs have an insulating wall and a wall at a constant temperature. The other walls of the microchannel are insulated. Slip boundary condition is imposed on the walls and the temperature jump is ignored. The effect of different parameters such as Reynolds number, Hartmann number, slip coefficient and volume fraction of nanoparticles on the velocity and temperature distributions are investigated. The results are presented as the velocity and temperature profiles and local and average Nusselt numbers. The results demonstrate that the heat transfer rate and Nusselt number increase with the Reynolds number and the intensity of the magnetic field. Also, an enhancement in the volume fraction of nanoparticles and the slip coefficient leads to an increase in the heat transfer rate.

Numerical Study on Hydrothermal Performance Factor Using Jet impingement and Nanofluid

In this study, thermal-hydraulic performance of a confined slot jet impingement with Al2O3-water nanofluid has been numerically investigated over Reynolds number ranges of 100-1000. Two triangular ribs are mounted at a heated target wall; one rib located on the right side of the stagnation point and another one located on left side of the stagnation point. The governing momentum, continuity and energy equations in the body-fitted coordinates terms are solved using the finite volume method and determined iteratively based on SIMPLE algorithm. In this study, effects of Reynolds number, rib height and rib location on the thermal and flow characteristics have been displayed and discussed. Numerical results show an increase in the average Nusselt number and pressure drop when Reynolds number and rib height increases. In addition, the pressure drop and average Nusselt number increases with decrease the space between the stagnation point and rib. The maximum enhancement of the average Nusselt number is up to 39 % at Reynolds number of 1000, the rib height of 0.3, rib location of 2 and nanoparticles volume fraction of 4%. The best thermal-hydraulic performance of the impinging jet can be obtained when the rib height of 0.2 and rib location of 2 from the stagnation point with 4% nanoparticles volume fraction.

Numerical Investigation of a Solar Air Heater (SAH) with Triangular Artificial Roughness Having a Curved Top Corner

In the present study, numerical investigation of two-dimensional incompressible air flow through a solar air heater (SAH) with a triangular artificial roughness having a curved top corner is performed using ANSYS Fluent 15.0 based finite volume method. The geometrical parameters of the triangular ribs having a curved top corner such as the roughness height ratio (e/D = 0.021, 0.03 and 0.042) and the roughness pitch ratio (p/e =7.14, 10.70, 14.28 and 17.86) have been investigated for a varied Reynolds number between 3800 to 18000. Flow and energy governing equations were solved with the accosiation of two transport equation for the turbulence kinetic energy k and the dissipation rate ɛ. The RNG k-ε turbulent model have been selected to be the more appropriate turbulence model for the present study. Results indicates that the values of Nusselt number and friction factor strongly depend on the roughness relative height e/D, relative pitch p/e and the value of Re number. The best solar air heater performance could be obtained for e/D=0.042 and p/e=7.14.

Numerical and Experimental investigation of heat transfer of triangular ribs in divergent duct

Numerical and Experimental investigation of heat transfer of triangular ribs in divergent duct

Numerical Analysis Of Interrupted Microchannel Heat Exchanger With Triangular Ribs On The Side Walls

A numerical analysis on an interrupted microchannel heat exchanger (MCHS) with triangular ribs on the side walls is conducted to study fluid flow and heat transfer characteristics in microchannels. Numerical model is simulated using silicon as solid and water as coolant. Numerical analysis is done by considering viscous dissipation, Temperature dependent thermophysical properties and entrance effects. Pressure drop and temperature across the domain is studied. It is found that triangular ribs can considerably increase heat transfer but comes with a penalty of high pressure drop. Offset arrangement of triangular ribs is more effective due to improved heat transfer and reduction in pressure drop.

Feasibility study on triangular perfobond rib shear connectors in composite slab

This paper attempts to emphasize the experimental study on feasibility of Triangular perfobond rib shear connector in composite slab with cold formed steel beam. This rib shear connector is a feasible alternate to the existing type of connectors like shear studs etc., this perfoplate has triangular hole of size (30 × 50 mm) in the CFS plate of (500 × 40 mm) with two different positioning of triangular hole, one facing the flange (TR1) and the other facing opposite to flange (TR2). Vertical compressive force applied in Universal Testing Machine to find the shear capacity of the new connector in a composite slab. There is an increase in composite interaction which results in both the triangular perfobond have approximately equal load carrying capacity, but the slip behaviour is comparatively higher in the triangle head facing opposite to the flange (TR2). According to the failure phenomenon in ultimate loading state, the failure mechanism of perfobond rib shear connectors was analysed and the results indicates that brittle failure always occurs in perfobond rib connectors. The influence of the perfoplate connector configuration on the load bearing capacity and structural improvement was discussed.

Thermo-hydraulic performance of rectangular channel roughened with combined semi-circular and triangular ribs

Ribs of different geometrical shapes are used on the surface for heat transfer enhancement. However, the combination of different shapes of ribs on the heat transfer surface is found less in literature. The objective of the present investigation is to design ribs roughness pattern of semi-circular, triangular, and hybrid ribs (combined semicircular and triangular ribs) on the bottom heated surface of the channel. Then, find optimum configuration and geometry of ribs pattern that has highest thermo-hydraulic performance. This combination of different shape of ribs pattern may be used for cooling of the heated channel such as in gas turbine blade, and high-temperature gas cooled reactors, etc. The rib pitch to rib height ratio (p/e) is considered in the range from 6.6 to 53.3 and Reynolds number in the range from 12,640 to 52,410. Turbulence model used for analysis is shear stress transport (SST) k-ω model. The effect of different geometry and configuration of ribs pattern on Nusselt number and friction factor are investigated and compared with that of the smooth channel. It is found that the Nusselt number (Nu) is maximum at p/e of 13.3 and friction factor (f) is maximum at p/e of 6.6 for all geometry of ribs pattern considered. Furthermore, Thermal enhancement factor (TEF) is determined for all geometry and configurations of ribs pattern. It is found that Thermal enhancement factor is maximum for hybrid ribs (1.34) at p/e of 13.3 and Reynolds number of 12,640 from the geometry and configuration of ribs pattern considered.

A conjugate heat transfer analysis of performance for rectangular microchannel with trapezoidal cavities and ribs

A numerical investigation has been taken up to assess the efficacy of a design innovation for rectangular microchannel heat sink by applying the concepts of maximization of thermal performance (TP) and minimization of entropy generation (EG). The channel is conceived as a serial arrangement of modifying units, each with a rib symmetrically located between trapezoidal cavities (TRC) on opposite side walls. Based on SIMPLEC algorithm for the flow along with conduction through the bounding walls and the internal ribs, a three dimensional laminar-flow conjugate heat-transfer study has been carried out between Reynolds number (Re) of 140 and 600 following a validation against a representative numerical and experimental study. A comparison among the predictions of constant fluid property model and models incorporating their realistic variations with temperature has shown the cooling to be dominated by convection, of course more strongly at higher Re. Substantially higher thermal conductivity of copper than that of silicon have revealed moderate increase in bulk fluid temperature and even lower increase of substrate temperature. Four different rib structures have been considered that are rectangular (RR), backward triangular (BTR), forward triangular (FTR) and diamond (DR). The predictions against Re indicated the best TP with diamond rib combination (TRC-DR) and the highest EG with backward triangular rib combination (TRC-BTR). A notable contribution of this work is establishing the concept of minimization of EG under the constraint of given pumping power to be equivalent to the concept of maximization of TP. The effects of parametric variations of relative width and length of cavity and relative width and pitch of rib have been investigated and the highest TP has been predicted around Re of 328.

Heat transfer enhancement of turbulent forced nanofluid flow in a duct using triangular rib

A Renormalized Group (RNG) k-ε model is used to numerically simulate the turbulent nanofluids flow in a duct using triangular rib. The governing equations are solved by using the finite volume method (FVM). The parameters examined in this study are; the effect of nanoparticles type, the nanoparticles volume fraction, the nanoparticles diameter, and Reynolds number to show their effect on the heat transfer coefficient and friction coefficient. The nanoparticles concentration is ranged from 1% to 6% and Reynolds number is ranged from 4000 to 32,000. Nanofluids; Al2O3-EG, CuO-EG and SiO2-EG are explored here. The results show that for the case of SiO2-EG, 6 vol% and Re = 32,000, the average Nusselt number is 84.45% higher than the case of Re = 4000. A slight increase in the friction coefficient is observed when the nanoparticles concentration increases.

Конструкция плиты для сборных дорожных покрытий

Experience in the operation of prefabricated concrete pavements with intensive traffic of heavy vehicles has shown that despite a high strength of the concrete slabs themselves it is necessary to arrange strong foundations. While laying concrete on the ground residual deformations are accumulating in it due to pressures which are initiated by elastically bending plates when vehicles are passing that leads to formation of voids under the plate and cracks in the plate itself. In order to increase rigidity of the plate (reduction of its settlement during the passage of vehicles) the author has proposed to arrange plates with two longitudinal ribs, and the plates themselves are to be laid on loose soil mixed with cement. The ribs are proposed to be placed on roll bars, i. e. symmetrically with respect to a longitudinal axis of the plate at a distance from each other which is equal to the distance between wheels of the calculated vehicle on one axis. In order to determine dependence of plate rigidity on a shape and a size of a cross section in longitudinal ribs calculations have been made while using a PC “Lira” and a finite element method. A finite element model of the plate has included 19152 nodes and 18943 finite elements. An elastic foundation has been modeled by vertical elastic links which are in every bottom node. The plate has been loaded with a load which is equivalent to the load from a calculated vehicle wheel at four points: a wheel in the middle of the plate; a wheel on the corner of the plate; two wheels at the same time on the line which is perpendicular to the longitudinal axis of the plate and located at the beginning (or end) of the plate; two wheels at the same time on the line which is perpendicular to the longitudinal axis of the plate and passing through its center. The following forms of a longitudinal rib having the same crosssectional area have been studied at the beginning: triangular, oval (semicircle) and rectangular. In the context of plate rigidity increase the most optimal form has been a triangular shape. Height differences in such a plate are the least in case of load action. So, for example, in comparison with a typical plate (plate without longitudinal ribs), presence of longitudinal ribs of triangular cross – section increases plate rigidity by an average of 50 % depending on the location of the calculated wheel on the plate (39–64 %). After determining an optimal shape of cross section for longitudinal ribs the dependence has been found for plate rigidity and it depends on a height of longitudinal triangular ribs. While having a constant volume of the plate and a constant a size of the rib base (32 cm) (approximate width of a calculated vehicle wheel) a rib height and a plate thickness have been changed. The calculations have made it possible to determine dependence of the plate rigidity on a height of a longitudinal rib. It has been determined that as for the given volume and dimensions of the plate the optimal rib height is 25 cm.

Numerical and Experimental Investigation of Heat Transfer Features in a Square Duct with Internal Ribs

In this work, experimental investigation and numerical prediction were completed to study the heat transfer for disturbed flow in square passage heated from upper and lower aspect through the use of technology to heighten the heat transfer action by the use of different ribs shapes (semicircle, triangular and square) with the same surface area and height, distributed on the superior and inferior aspect of the heated channel. The experimental part included designing and manufacturing test apparatus and run the tests through operational parameters (Reynolds number 10460-40500) and heat flux (138-6888) W/m^2. While the design parameters included different ribs shapes (circular, triangular and square). Numerical investigation was done by using ANSYS FLUENT14.0 program, depending on Navier–Stokes equations, application of turbulence model k-ε and energy equation for the air were implemented for the same experimental conditions for all ribs type. In conclusion, the additions of ribs make noticeable enhance of the heat transfer compared to without ribs. Square ribs provide the best enhancement in heat transfer by (28.22-58.23) % compared to without ribs. Then comes the triangular and circular ribs that provide enhancement by (20.14-45.62) (10.87-28.13) % respectively. In addition to that, arrange the ribs in staggered pattern on the upper and lower aspect give the best heat transfer.

Comparative study on heat transfer enhancement of nanofluids flow in ribs tube using CFD simulation

AbstractThis study presents, a numerical investigation of two‐dimensional turbulent nanofluids flow in different ribs tube configurations on heat transfer, friction, and thermal performance coefficients using ANSYS‐FLUENT software version‐16. Governing equations of mass, momentum, and energy have been solved by means of a finite volume method (FVM). Four types of nanoparticles namely; Al2O3, CuO, SiO2, and ZnO with volume fraction range (1%‐4%) and different size of nanoparticles (dp = 30 nm, 40 nm, 50 nm, and 60 nm) with various Reynolds number (10 000‐30 000) in a constant heat flux tube with rectangular, triangular, and trapezoidal ribs were conducted for simulation. The results exhibit that Nusselt number for all cases enhanced with Reynolds number and nanofluid volume fraction increases. Likewise, the results also reveal that SiO2 with volume fractions of 4% and diameters of nanoparticles of 30 nm in triangular ribs offered the highest Nusselt number at Reynolds number of Re = 30 000. In addition, the higher value of thermal performance factor was obtained at Reynolds number of Re = 10 000.

A comparative analysis of thermo-hydraulic performance of a roughened solar air heater using various rib shapes

ABSTRACT The thermal efficiency of the solar air heater (S.A.H.) is enhanced by introducing various artificial roughness geometries on the absorber surface. Artificial roughnesses in the form of a chamfered rib, right angle triangular and reverse L-shaped ribs, invented from square rib are presented. A comparative thermohydraulic analysis of these ribs is carried out using experimental, Computational Fluid Dynamics (C.F.D.) and analytical investigation. The experiments are carried out using rib height (e = 0.7,1 and 1.4), relative roughness pitch (P/e = 7.14 to 35.71), relative roughness height (e/D = 0.021, 0.03 and 0.042), Reynolds number (Re = 3800 to 18000) and duct aspect ratio (W/H= 5).The effect of rib shape, rib height (e), pitch (P), relative roughness pitch (P/e), relative roughness height (e/D), chamfer angle (α) and Reynolds number (Re) on heat transfer and friction flow is evaluated. Experimental results are validated using C.F.D. code ANSYS FLUENT 14.5, by simulating two-dimensional computational domain of roughened S.A.H. Based on the experimental results correlations for the Nusselt number and friction factor are derived. A mathematical model has been developed to investigate the effect of geometrical and operating parameters on the thermal and effective efficiency of a roughened S.A.H.