Saving energy resources requires a continuous improvement of the power equipment. The present study aims to develop new designs of double pipe heat exchanger (DPHE) to improve the heating/cooling processes at the lowest possible pumping power. Therefore, thermal performance investigation of three configurations of DPHE has been carried out. These configurations are circular wavy DPHE (DPHE), plain oval DPHE (DPHE), and an oval wavy DPHE (DPHE). In addition, the conventional DPHE (DPHE) has been employed as a reference heat exchanger, and a validated CFD approach is adopted to perform the current investigation. The findings reveal that, DPHE yields the highest Nusselt number (Nu) which is up to 28% with respect to DPHE. In addition, data of pressure drop (ΔP) of DPHE are found the highest followed by those of DPHE, whereas DPHE is found to yield the lowest ΔP. Furthermore, thermal performance factor () has been considered, and DPHE is found to own the highest of all investigated DPHEs. In conclusion, the oval tubes have shown better heat transfer characteristics with respect to their circular counterparts in general, in particular plain oval DPHE.

We have developed a numerical model based on Metropolis Monte Carlo (MC) and the weighted histogram analysis method (WHAM) that enables the calculation of the absolute binding free energy between functionalized nanocarriers (NC) and endothelial cell (EC) surfaces. The binding affinities are calculated according to the free energy landscapes. The model predictions quantitatively agree with the analogous measurements of specific antibody coated NCs (100∼nm in diameter) to intracellular adhesion molecule-1 (ICAM-1) expressing EC surface in cell culture experiments. The model also enables an investigation of the effects of a broad range of parameters that include antibody surface coverage of NC, glycocalyx in both and conditions, shear flow and NC size. Using our model we explore the effects of shear flow and reproduce the shear-enhanced binding observed in equilibrium measurements in collagen-coated tube. Furthermore, our results indicate that the bond stiffness, representing the specific antibody-antigen interaction, significantly impacts the binding affinities. The predictive success of our computational protocol represents a sound quantitative approach for model driven design and optimization of functionalized nanocarriers in targeted vascular drug delivery.

In this study, a more precise and cost-effective method is used for studying the drug delivery and distribution of magnetic nanoparticles in fluid hyperthermia cancer treatment, and numerical methods are employed to determine the effect of blood circulation on heat transfer and estimate the success of cancer treatment. A combination of numerical, analytical, and experimental researches is being conducted, which illustrates the essential role of numerical methods in medical and biomedical science. Magnetic NanoParticles' distribution and effects of infusion rate on the treatment are also discussed by considering the real distribution of MNPs. To increase accuracy and reduce costs in the in-vitro section, direct cutting and image processing methods are used instead of MRI. Based on the results of this section, with a tenfold increase in the infusion rate (4 μl/min to 40 μl/min), the penetration depth increases by 1 mm, which represents a nearly 17 percent increase. Concentrations of MNPs also decrease significantly at higher infusion rates. The simulations of heat transfer reveal that maximum temperatures occur at the lowest infusion rate (1.25 μl/min), and blood flow also has a significant effect on heat transfer. With an increase in the infusion rate, necrosis tissue recedes from the tumor center and approaches the border between the tumor and healthy tissue. Results also show that, in lower MNPs' concentrations, higher infusion rates result in better treatment even though minimum infusion rates are suggested to be the best rates to facilitate distribution and treatment.

Additive manufacturing has received significant interest in the fabrication of functional channels for heat transfer; however, the inherent rough surface finish of the additively manufactured channels can influence thermal performance. This study investigates the impact of roughness on the thermo-fluid characteristics of laminar forced convection in rough minichannels. A numerical model was developed to create 3D Gaussian roughness with specified root-mean-square height. The finite volume method was used to solve the conjugate heat transfer of developed laminar flow in square minichannels. For Reynolds numbers ranging from 200 to 1600, the simulation results indicated enhanced heat transfer and increased flow resistance as Reynolds number increases, compared to a smooth minichannel, where effects on heat transfer and flow friction were negligible. For channels with relative roughness (root-mean-square height to channel hydraulic diameter) of 0.0068, 0.0113, and 0.0167, increasing the Reynolds number led to increased friction factor by 1.56, 1.71, and 2.91%, while the Nusselt number was enhanced up to 0.03%, 32.74%, and 46.05%, respectively. Heat transfer reduced in roughness valleys due to the presence of local low-velocity fluid in these regions; however, recirculation regions can occur in deep valleys of high roughness, increasing heat transfer and flow friction. Heat transfer was enhanced over roughness peaks due to flow impingement on the windward face of roughness as well as intensified energy transfer to the channel wall from roughness. Moreover, surfaces with higher roughness have a greater number of high peaks providing a thermal-flow path of a larger area and a thermal conductivity greater than that of the fluid.