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Due to the fact that modern technologies are getting smaller and more compact and are anticipated to perform better, there has been an increase in interest in heat transfer enhancement employing hybrid nanofluids in tubes and channels in recent years. This study seeks to establish an outward saw tooth corrugated wall model-based predictive friction characteristic for internal tube flow. Computational Fluid Dynamics (CFD) was used to simulate the model numerically. The response behaviour study was then conducted utilising the Design of Experiment (DOE) and the Response Surface Methodology (RSM). The established surrogate model has led to the consideration of RSM. In this study, the DOE was executed by utilising the Box-Behnken Design (BBD) method with two-level factorial by considering three parametric factors which are: (a) 10000 to 30000 axial Reynolds number, Re, (b) 1mm to 4mm wave amplitude, a, and (c) 5mm to 20mm wavelength, lw. The results showed that the expected response surface values are consistent with the CFD values and that the predictive model is therefore reliable. The R-squared (R2) value is 98.25%, indicating that the model can predict new observations. The wavelength and wave amplitude show significant factors influencing the friction factor which is -0.11235 and 0.14861 respectively and this is based on the normal plot of the effect from the regression model from RSM. These results provide data for estimating the geometric characteristics of tube corrugated wall.

In recent years, there has been an increasing interest in heat transfer enhancement using nanofluids in channels due to current devices become smaller and more compact and are expected to perform better. Thus, we attempt to introduce hybrid nanofluids flow in a straight pipe using Ansys Fluent software. The simulation was prepared with certain specific parameters such as the hydraulic diameter is set at 10mm, the flow is a continuum, the Reynold number in the range of 5000 to 30000, k-e turbulent model used in this simulation, the inlet temperature 297 K, and the uniform temperature along the pipe at 313 K. This study was carried out on Al2O3+Cu / water hybrid nanofluids to analyse the thermal improvement and friction factor of nanofluids occur in a straight pipe. Then, the numerical results obtained were compared between mono and hybrid nanofluids. It was found that the mono nanofluids at 1% and 4% indicate a significant increase in Nusselt number at 17% and 24% respectively and hybrid nanofluid increase at 2% to 5.6% compared to base fluid. Whereas the friction factor remains similar for all the nanofluids. However, the performance evaluation criterion (PEC) has shown that hybrid nanofluids remain lower than mono nanofluids.

A new meshless-based solver has been used to study the deformation of flexible structure due to water dam break. This meshless Fluid Structural Interaction (FSI) solver couples the Smoothed Particle Hydrodynamics (SPH) and Lattice-Spring Model (LSM). SPH and LSM are used to model the motions of fluid and solid particles, respectively. As both are essentially particle-based methods, the force coupling at the interface is straightforward. The numerical results have been compared with the benchmark numerical solutions of dam break problem and good agreement has been found.