since knowledge on hydrodynamic torque of a butterfly valve is very important for butterfly valve design, its hydrodynamic torque is investigated in this paper. in reality, the investigation of the loss coefficient and torque from some experiments will take a long time and a lot of money. this paper presents a statistical study of the flow past the butterfly valve in a static analysis using com...

active flow control has great importance in design of flying objects in general and control flaps in particular. using dielectric barrier discharge as plasma actuators over control flaps can cause a change in position of separation point or can eliminate it. this new flow control device produces a body force that causes generating a micro wall jet. the present study aims to investigate experime...

Various problems concerning the effects of the boundaries of the ocean on the propagation of pressure waves In the ocean are considered. The propagation of a transient pressure wave In a wedge shaped region of fluid Is treated. This Is the model chosen to describe the situation In which an underwater explosion takes place In a coastal ocean region which Is characterized by a strongly sloping bo...

b number of arc segments within curve CF thrust coefficient CF;w weighted thrust coefficient Cx nozzle length-weight coefficient E numerical error k turbulent kinetic energy, m s−2 L total contour axial length, m Ma Mach number P static pressure, Pa r radius, m TW thrust-to-weight ratio x horizontal distance, m y vertical distance, m ε turbulent dissipation rate, m s−3 θ angle, deg ω specific d...

Steady incompressible flow around a circular cylinder in an external magnetic field that is aligned with fluid flow direction is studied for Re (Reynolds number) up to 40 and the interaction parameter in the range 0 ≤N ≤ 15 (or 0 ≤M ≤ 30), where M is the Hartmann number related to N by the relation M = √2N Re, using finite difference method. The pressure-Poisson equation is solved to find press...

BACKGROUND Morbidly obese patients are at elevated risk of perioperative pulmonary complications, including airway obstruction and atelectasis. Continuous positive airway pressure may improve postoperative lung mechanics and reduce postoperative complications in patients undergoing abdominal surgery. METHODS Forty morbidly obese patients with known obstructive sleep apnea undergoing laproscop...

1. A new non-invasive test was developed to assess calf muscle pump function: the supine venous pump function test. The technique uses strain-gauge plethysmography and is performed in the supine position. The method is superior to other non-invasive methods because basically the most essential haemodynamic parameter, venous pressure decrease, is used by properly converting venous volume measure...

BACKGROUND To evaluate the relevance of diastolic perfusion time on the mechanisms underlying stress-induced ischemia, 16 patients with coronary artery disease and seven patients with syndrome X underwent five randomized stress tests (upright and supine exercise with and without therapy, transesophageal atrial pacing). METHODS AND RESULTS Exercise duration Time to 0.1 mV ST segment depression...

In this prospective study, the effectiveness and biomechanical factors of spinal orthoses in the treatment of moderate adolescent idiopathic scoliosis (AIS) patients were investigated. In the first 20 months of orthotic treatment, the values of standing AP Cobb's angle, apical vertebral rotation, lumbar lordosis as well as thoracic kyphosis showed significant reduction (P<0.05), however, the an...