Nusselt number and friction characteristics of solar air heater roughened with novel twisted V-shaped staggered ribs using liquid crystal thermography

Kumar, Dheeraj; Layek, Apurba

doi:10.1016/j.renene.2022.11.007

Cited by 20 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The blower bills are increased by frictional losses as extra power is needed to create suction inside the duct so that fluid can flow as intended [4]. Many scientists have investigated the impacts of different rib designs on the heat transfer coefficient, the impact of friction factor on the pressure drop across the orifice meter (Δp d ) and thermal-hydraulic performance parameter (THPP) [5]. There is still a need to identify the best rib geometry -pattern, pitch and position for improved thermal and hydraulic performance.…”

Section: Nomenclaturementioning

confidence: 99%

See 1 more Smart Citation

Experimental investigation and performance prediction of SAH using different arc rib roughness geometries – A comparative study

Singha,

Lanjewara

2024

Archives of Thermodynamics

View full text Add to dashboard Cite

This study aims to investigate and compare the thermal performance of a solar air heater using a passive technique to enhance heat transfer between the absorber plate and the flowing fluid. The technique involves generating turbulence near the heat transferring surface through the use of artificial rib roughness. The study focuses on two different novel roughness geome-tries: full symmetrical arc rib roughness and half symmetrical arc rib roughness. By introducing additional gaps and varying the number of gaps in the roughness geometries, the study examines their effects on the solar air heaters thermal performance. The artificially roughened surface creates different turbulent zones, which are essential to the development of different types of turbulence in the vicinity of the heat transferring surface. The study finds that an optimal escalation in Nusselt number and friction factor by 2.36 and 3.45 times, respectively, occurs at certain gap numbers as 6 and ng as 5 for full symmetrical arc rib roughness. The maximum thermal-hydraulic performance parameter of 1.66 is attained at a Reynolds number of 6 000. The study also conducts correlation, mathematical modeling, and performance prediction under different operating circumstances.

show abstract

Section: Nomenclaturementioning

confidence: 99%

“…Discrete multi-V shaped and staggered rib geometry performs better than discrete V-shaped with a staggered element [7]. A staggered V-shaped twisted rib was investigated using the LCT technique to visualize the fluid flow [5]. The thermal efficiency of SAH was improved with the use of double glazed finned steel absorber plate [8].…”

Section: Greekmentioning

confidence: 99%

Experimental investigation and performance prediction of SAH using different arc rib roughness geometries – A comparative study

Singha,

Lanjewara

2024

Archives of Thermodynamics

View full text Add to dashboard Cite

show abstract

“…3 The poor heat transfer coefficient (h) of flowing fluid leads to diminished efficiency of SAH. 4 Low SAH efficiency is a result of a viscous sub-layer over absorber plate. A higher h rate is obtained by disturbing the laminar sub-layer by providing an rib element on the absorber surface.…”

Section: Introductionmentioning

confidence: 99%

“…Density of air (r o ) at outlet temperature (T o ): Rate of mass flow (m):m = C d 3 A 2 3 2 3 r o 3 DP ð Þ o 1 À b4 Density of air (r f ) at T f : Velocity of air (V):…”

mentioning

confidence: 99%

Thermal performance of solar air heater having discrete symmetrical arc rib with staggered rib roughness

Singh

Lanjewar

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

This paper investigates physics of forced flow underneath the absorber plate in solar air heater (SAH) integrated with new arc geometry namely discrete symmetrical arc rib with staggered rib roughness. This article signifies the impact of roughness pitch relative to rib height (p/e) on the thermal performance of rectangular roughened SAH duct having discrete symmetrical arc rib with staggered rib (present study). Novel arc rib geometry (present study) is achieved by providing an additional gap in a significantly long continuous arc segment of existing best arc rib geometry to break the boundary layer reformation along it. Range of parameters considered for experimental run for new geometry were Reynolds number (Re) as 3000–15,000, roughness pitch relative to rib height (p/e) of 6–14, flow attack angle (α) of 30°, staggered rib pitch relative to roughness pitch (p′/p) of 0.4, number of symmetrical gap over full arc (Ng) as 6, number of additional gap in symmetrical arc elements (ng) as 5, gap width relative to rib height (g/e) as 3, rib height relative to hydraulic diameter (e/Dh) as 0.043, relative gap position (d/w) and additional gap width relative to rib height (g′/e) as 0.65 and 1 respectively. Five different roughened test plate with the variation of p/e as 6, 8, 10, 12, and 14 were tested. Optimum augmentation is perceived in Nu at p/e as 10 and for f at p/e as 8. Maximum thermo-hydraulic performance parameter (THPP) is achieved at p/e as 10 that corresponds to Re as 6000. Correlation, mathematical model, performance prediction and economic evaluation have also been done under different operation conditions.

show abstract

“…[34] examined SAH performance using V-Rib roughness with aligned gaps and staggered elements. Kumar D and Layek A [35] investigate the THP in a SAH with twisted V-shaped staggered ribs.Halder A. et al [36] how wavy patterns on the surface of a SAH can make it work better. The researchers utilised computer simulations to explore how these patterns impact airflow and heat transfer.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Heat Transfer Performance in a Solar Air Heater using discrete V-Rib Geometry with Gap

Dubey,

Prakash

2023

Preprint

View full text Add to dashboard Cite

Solar air heater (SAH) have emerged as promising technology for harnessing solar energy in a sustainable and environmentally friendly manner. Numerous techniques for enhancing heat transfer methods have been investigated to improve thermal performance. This study investigated how discrete V rib coarseness effect the performance of SAH. The experiments were conducted under different operating conditions, including rib pitch-to-height ratios (p/e) of 8, 10, and 12, an angle of inclination of 60 degrees, width to height of duct (W/H) 8, gap width to depth 4, Centre distance between two successive ribs of 0.5, number of gaps on each side of 1 and Reynolds number of 4000 to 145000. Experimental data indicated that the SAH equipped with the discrete V-rib geometry and gap achieved higher heat transfer rates compared to traditional SAH designs without this feature. In this case, the Nusselt number (Nu), Thermo-hydraulic performance parameters (THPP) and friction factor (f) increased by 3.62, 3.22, and 2.85, respectively, compared to a flat plate. These values indicate the improvements achieved by the artificial rib coarseness in enhancing heat transfer compared to a flat surface. Furthermore, study demonstrated that the new discrete V-rib geometry with a gap outperformed to existing designs.

show abstract

Nusselt number and friction characteristics of solar air heater roughened with novel twisted V-shaped staggered ribs using liquid crystal thermography

Cited by 20 publications

References 27 publications

Experimental investigation and performance prediction of SAH using different arc rib roughness geometries – A comparative study

Experimental investigation and performance prediction of SAH using different arc rib roughness geometries – A comparative study

Thermal performance of solar air heater having discrete symmetrical arc rib with staggered rib roughness

Enhanced Heat Transfer Performance in a Solar Air Heater using discrete V-Rib Geometry with Gap

Contact Info

Product

Resources

About