Numerical investigation has been carried out on heat transfer and friction factor characteristics of copper-water nanofluid flow in a constant heat-fluxed tube with the existence of new configuration of vortex generator using Computational Fluid Dynamics (CFD) simulation. Two types of swirl flow generator: Classical twisted tape (CTT) and Parabolic-cut twisted tape (PCT) with a different twist ...

Pressure, particularly over bony prominences such as the ischium, trochanter, elbows, heels and other anatomic sites, leading directly to tissue damage and restricting blood flow creating areas of cell death and ischaemia, has been widely recognised as a risk factor for pressure ulcers (PU) (Grey et al, 2006; Gefen et al, 2008; National Institute for Health and Care Excellence [NICE], 2014). Th...

We review the thermal characteristics of all-metallic sandwich structures with two dimensional prismatic and truss cores. Results are presented based on measurements in conjunction with analytical modeling and numerical simulation. The periodic nature of these core structures allows derivation of the macroscopic quantities of interest—namely, the overall Nusselt number and friction factor—by me...

Empirical Colebrook equation implicit in unknown flow friction factor (λ) is an accepted standard for calculation of hydraulic resistance in hydraulically smooth and rough pipes. The Colebrook equation gives friction factor (λ) implicitly as a function of the Reynolds number (Re) and relative roughness (ε/D) of inner pipe surface; i.e. λ0=f(λ0, Re, ε/D). The paper presents a problem that requir...

* email: [email protected] John Charnley was the first who introduced low friction arthroplasty concept. In November 1962, he implanted a hip prosthesis using a high density polyethylene (HDPE) cup, which articulated with a stainless steel femoral head of 22,25 mm diameter. The principle of the low friction arthroplasty has remained the same ever since. Because HDPE have not a goo...

PURPOSE About 70% injury of gymnasts happened during landing - an interaction between gymnast and landing mat. The most injured joint is the ankle. The current study examined the effect of mechanical properties of landing mat on ankle loading with aims to identify means of decreasing the risk of ankle injury. METHOD Gymnastic skill - salto backward stretched with 3/2 twist was captured by two...

We extend the analysis of the friction factor for turbulent pipe flow reported by G. Gioia and P. Chakraborty [Phys. Rev. Lett. 96, 044502 (2006)] to the case where drag is reduced by polymer additives.

Since there are backlash friction and time-varying stiffness, the characteristics of gear pair has strong nonlinearity. When a gear has faults such as pitting, spalling and tooth breakage, there are often some nonlinear characteristics as super-harmonics or sub-harmonics along with vibration signal. These characteristics will cause some difficulty for fault diagnostics, so it is necessary to st...