Table 1 Review previous studies concerning nanofluids and their interaction with impinging jets.

Tie et al.¹⁰

Cu-water nanofluids

• Suspended nanoparticles significantly improve heat transmission in base fluids, with increased volume percent of nanoparticles leading to higher heat transfer coefficients.

• Certain combinations of nanofluids may reduce heat transfer coefficient.

Kareem et al.²⁰

CuO-water nanofluid

• Heat transfer is boosted by volume fraction percentage.

• Nusselt number increased with nozzle-target plate distance.

Teamah et al.³⁷

Al2O3–water

• Heat transfer rises with increasing Reynolds number at constant volume concentration.

• CuO has higher heat transfer than Al2O3, whereas TiO2 has lower heat transmission.

Wongcharee et al.⁴²

CuO/water nanofluids

• The Nusselt number decreases as there is rise in jet-plate gap-nozzle diameter ratio.

• Under comparable operating conditions, nanofluids volume of 2.0% and 3.0% delivers higher magnitude of Nusselt numbers.

Naphon et al.³⁹

TiO2nanofluids jet impingement h

• In a micro-channel heat sink, concentrations of nanofluids significantly alters heat transfer.

• With rise in nozzle height and lowering the diameter, the rate of heat dissipated increases.

Amjadian et al.⁴⁰

Cu2O–water

• The highest value of the heat transfer rate is observed near the stagnation point.

• The fluid jet strikes the centre of the disc, causing acceleration in the intermediate areas as the fluid flows radially.

Boudraa & Bessaïh⁴¹

Binary hybrid nanofluids

• The use of Al2O3 nanoparticles in spherical form and MgO nanoparticles in platelet form resulted in higher heat transfer.

• The stagnation point has the highest Nusselt number.

Mohammadpour et al.⁴²

SiC nanofluids

• The PV temperature was greatly influenced by the inlet temperature of nanofluids, resulting in increased output power when the inlet temperature was lower.

Present Study

Straight slot impingement jets with TiO₂/H₂O nanofluid flow through square channel

• The Reynolds number (Re) varies from 8000 to 17,000, slot jet height ratio \(\:({H}_{jet}/{D}_{hd})\) varies from 0.3 to 0.6, spanwise jet pitch ratio \(\:({P}_{span}/{D}_{hd})\) ranges from 0.18–0.23 and streamwise jet pitch ratio \(\:({P}_{stream}/{D}_{hd})\) ranges from 0.88–0.97.