In this work, the numerical analysis concentrates on investigating thermal flow patterns, pressure drops, varying velocity components and heat transfer behaviour. Impacts of four parameters on the enhancement of thermohydraulic performance are carried out using three-dimensional calculations employing CFD techniques: different spacing, diameter, number and distance for dimples were investigated. Additionally, utilising a design of experiments (DoE) strategy together with the Taguchi technique (TT) and response surface methodology (RSM), the impacts of the factors listed below are optimised. The results indicated that the different flow fields and heat transfer patterns were because of the use of depressions on the tube's inner surface. A comprehensive flow investigation with the dimple and tube wall was established to explain the mechanism of pressure drop and heat transfer change. The results of orthogonal experiments show that the optimal design of the spiral tube in this investigation using computational fluid dynamics using DoE, RSM and TT has a temperature difference and heat transfer coefficient of about 35.75% and 36.1% higher improved pipes. The results show a high PEF value greater than 1. According to the above results, various design applications require flow hydrodynamic analysis and heat performance enhancement.