A closed-form analytical method is presented to predict a Mach number, pressure, and temperature for scramjet combustor where variable area, friction, heat addition effects are simultaneously present. The was verified against classical solutions of quasi one-dimensional isentropic flow, Fanno Rayleigh flow. number predicted by the agreed within 0.45%, 0.01%, 0.83% with solutions, respectively. results were compared Reynolds Averaged Navier–Stoke based computational fluid dynamics (CFD) model...

A three-dimensional numerical modeling of airflow in the human pharynx using an anatomically accurate model was conducted. The walls were assumed to be passive and rigid. results showed that pressure drop lies range 200-500 Pa. onset turbulence found increase by 40 percent. wide geometries covering three sleep apnea treatment therapies (CPAP, mandibular repositioning devices, surgery) modeled resulting flow characteristics investigated compared. confirmed laminar-to-turbulence transitional...

The study of the simultaneous development slip-flow and heat transfer in a microtube with internal fins has been conducted. It was found that rarefaction effects were more pronounced entrance region than fully developed for both friction factor Nusselt number. Minimal influence number on observed, but substantial numbers noted. Tubes larger fin height to enhance factor, while opposite observed An evaluation criterion used compare pressure drop microtubes without fins. results showed offers...

A recent bibliographic report is described that covers world literature, on enhanced heat transfer, dating back to 1861. The report, which available in electronic or hard copy format, contains 5676 references technical papers and reports, classified according enhancement technique mode of transfer.

Increasing demands on engine power to meet increased load carrying capacity and adherence emission norms have necessitated the need improve thermal management system of vehicle. The efficiency vehicle cooling strongly depends fan fan-shroud design and, designing an optimum has been a challenge for designer. Computational Fluid Dynamics (CFD) techniques are being increasingly used perform virtual tests predict optimize performance assembly. However, these CFD based optimization mostly single...

An experimental investigation of laminar flow and heat transfer in internally finned tubes was performed. Length-averaged measurements pressure drop for thermally developing were conducted both heating cooling situations as well low high flux cases using ethylene glycol the test fluid. The tests performed with fluid-to-fluid or which closely approximates constant wall temperature boundary conditions. Isothermal friction factors, diabatic Nusselt numbers measured fin geometry ranges 8 ≤ N 54,...

Developing mixed convection flow in internally finned tubes with variable viscosity was numerically investigated for a fin geometry range of 8 ≤ N≤24, 0.1 H 0.3 and an operating condition 50 Prin 1250, 0 Rain 107, qwd/kin 2000. The numerical model validated by comparison existing experimental data. Internal finning found to produce complex two-cell, buoyancy-induced vortex structure. results show that coring (retarded velocity the interfin region) leads poor heat transfer performance large...

Numerical investigation of laminarization low Reynolds number turbulent flow in a heated rotating vertical pipe is carried out using rotation-sensitized [Formula: see text] Shear Stress Transport (SST) model with modifications to include effects. The results show that rotation accelerates pipes and leads as much 72% deterioration heat transfer for typical inlet 5000 at 2. Rotation causes reduction the velocity gradients near-wall region. lower result rate production turbulence kinetic...

A numerical investigation of laminar mixed convection developing flow and heat transfer with variable viscosity in internally finned tubes helical fins constant wall temperature boundary condition was performed. The model validated by comparison experimental data able to predict experimentally measured friction factors Nusselt numbers an accuracy ± 10% for a wide range fin geometries operating conditions. parametric study conducted geometry ranges 8 ≤ N 54,0.03 H 0.1, 0 γ 45 degrees, where...

Flow and heat transfer in a twisted circular-sector duct are analyzed numerically for steady, fully developed, incompressible laminar flow with uniform-wall-temperature boundary condition. A rotating coordinate system is employed to account the twist. The friction factors Nusselt numbers predicted sector angles ranging from 15° 90°, Reynolds 1 1,000, Prandtl 100. Results show significant influence of twist on both numbers, particularly at large values numbers. Accurate correlations developed...

A Monte Carlo based stochastic numerical analysis of simultaneously developing mixed convection laminar flow and heat transfer with variable properties in a uniformly heated circular tube was carried out. The simulations were performed for heating large Prandtl number liquid wide range numbers (50 ≤ Pr 1000), Rayleigh (105 Ra 107), nondimensional flux values (100 qwd/k 1000). results show that the effect uncertainties is greater on friction factors uncertainty than it Nusselt uncertainty,...

Numerical analysis was carried out on the effect of uncertainties in fluid properties developing mixed convection flow and heat transfer with variable viscosity a uniformly heated smooth horizontal tube. The results indicate that property is greater apparent friction factors than it Nusselt numbers, numbers increase increasing entrance effects, viscosity, free effects. Overall, maximum predicted were around 8% 5%, respectively, for 10% uncertainty properties. Furthermore, these found to...

An experimental investigation of laminar flow and heat transfer in internally finned tubes was performed. Length-averaged measurements pressure drop for thermally developing were conducted both heating cooling situations as well low high flux cases using ethylene glycol the test fluid. The tests performed with fluid-to-fluid or which closely approximates constant wall temperature boundary conditions. Isothermal friction factors, diabatic Nusselt numbers measured fin geometry ranges 8 ≤ N 54,...