A major challenge in high-resolution x-ray free-electron laser-based coherent diffractive imaging is the development of aerosol injectors that can efficiently deliver particles to the peak intensity of the focused X-ray beam. Here, we consider the use of a simple convergent-orifice nozzle for producing tightly focused beams of particles. Through optical imaging we show that 0.5 μm particles can...

A solid object impacting on liquid creates a liquid jet due to the collapse of the impact cavity. Using visualization experiments with smoke particles and multiscale simulations, we show that in addition, a high-speed air jet is pushed out of the cavity. Despite an impact velocity of only 1 m/s, this air jet attains supersonic speeds already when the cavity is slightly larger than 1 mm in diame...

This study investigates the effect of nozzle-plate distance on the acoustic phenomena from a correctly expanded supersonic jet impinging on an inclined flat plate. In the authors’ previous study, the overall sound-pressure-level (OASPL) in the direction almost perpendicular to the plate from the impingement region became highest when the nozzle-plate distance was 15D (D, the nozzle exit diamete...

This paper reports on the results of experimental investigations on the performance of a jet pump operated under selected primary flows to optimize the related parameters. For this purpose a two-phase flow jet pump was used employing various profiles of nozzles as the primary device which was designed, fabricated and used along with the combination of mixing tube and diffuser. The profiles empl...

The presence of jet-marks, or jet-streaks, on the surface of hydroentangled nonwoven fabrics, is usually regarded as an undesirable outcome of the hydroentangling process. Jet-streaks degrade aesthetic features and physical properties of the resulting fabrics. Jet-streaks are associated with low tear strength along the machine direction and nonuniform appearance. Reducing or eliminating the occ...

A control law to improve jet flow mixing is presented. The control law employs a pair of actuators at the jet nozzle exit that act on the shear layers near the corners by blowing and subtracting fluid in an anti-symmetric fashion and a sensor downstream or at the nozzle exit with a time delay that measures the pressure difference across the nozzle diameter. A 2-D jet flow is numerically simulat...

BACKGROUND AND OBJECTIVE Cryogen sprays are used for cooling human skin during various laser treatments. Since characteristics of such sprays have not been completely understood, the optimal atomizing nozzle design and operating conditions for cooling human skin remain to be determined. MATERIALS AND METHODS Two commercial cryogenic spray nozzles are characterized by imaging the sprays and th...

A bubbly flow in a vertical miniature tube is analyzed theoretically. The liquid and gas phase are co-current flowing upward. The gas phase is injected via a nozzle whose inner diameter is 0.11mm and it is placed on the axis of the tube. A force balance is applied on the bubble at its detachment. The set of governing equations are solved by use of Mathematica software. The bubble diameter and t...

BACKGROUND AND OBJECTIVES Cryogen spray cooling (CSC) has become an integral part of dermatologic laser surgery because of its ability to remove selectively large amounts of heat from human skin in short periods of time, thereby protecting the epidermis from unintended thermal injury. The objective of the present study is to investigate the extent of lateral epidermal protection afforded by a c...

The evolution of co-rotating streamwise vortices in a canonical flat plate turbulent boundary layer ~thickness of the boundary layer d0.99525 mm) is studied. The vortices are produced by an array of inclined jets ~diameter D514 mm) with the same orientation ~skew angle b and pitch angle a of 45°!. The focus of the investigation is on the immediate vicinity of the jet exit and downstream locatio...