Experimental Investigation of 900 Intake Flow Patterns with and without Submerged Vanes under Sediment Feeding Conditions

In this study, two experiments were conducted in a 90⁰ water intake to study 3D flow patterns and sediment distribution using submerged vanes under sediment feeding and live-bed conditions. One column three vanes were installed at a 20⁰ angle maintaining for a water discharge ratio of q_r ~ 0.1. Three-dimensional mean and turbulent velocity components of flow in 90⁰ channel intake were measured by Acoustic Doppler Velocimetry (ADV). Flow characteristics of the intake structure area with no vanes are compared with those condition. Results showed that three vanes with single column reduced the amount of sediment by 20% in the intake diversion. In the downstream corner of the intake, high velocities were measured where scouring occurred. The vanes affected the intensity of secondary flow, turbulence energy, flow separation, and moved sediment deposition downstream of the main channel.

SAGD ESP Intake Design Improvement

One of the major challenges in SAGD Electrical Submersible Pump (ESP) operation is produced water flashing to steam when flowing pressure loss is significant, such as at an ESP intake. "Bottom Feeder" style intakes are a standard SAGD ESP intake which has been applied in the SAGD industry for over a decade. However,it was identified in recent years at ConocoPhillips's (CPC) Surmont Oilsands operations that Bottom Feeder intakes can lead to steam flashing in pump at the right conditions. The flashed steam causes significant cavitation in pump, which in turn causes severe motor load chattering. Further to that, steam locking in the pump can occur, which is called a "no flow event" (NFE) in the SAGD industry. ConocoPhillips and Baker Hughes have been working together to optimize SAGD ESPs by utilizing an integral intake to minimize the pressure loss across the intake ports. This would also streamline the connection between intake and pump housing to minimize pressure loss at these intake flow paths. The improved design has been tested in Surmont successfully, and the integral intake has become an optional intake to be applied in the well cases where steam flashing has been known to cause operation interruptions or ESP damages. This paper will review the process undertaken by CPC and Baker Hughes to study the ESP performance with the bottom feeder intake in comparison to the ESP performance with an integral intake.Design and field data will be presented and reviewed to highlight the performance of each system.

Numerical and experimental investigations of the early injection process of Spray G in a constant volume chamber and an optically accessible DISI engine

In this work, the Engine Combustion Network Spray G injector was mounted in the Darmstadt optical-accessible engine to study phenomena typical of multi-hole, early direct-injection events in spark-ignition engines characterized by tumble flow charge motion. Dedicated experimental measurements of both in-cylinder spray morphology and flow velocities before and after the injection process were carried out to assess the adopted numerical setup under real engine conditions. A dynamic secondary breakup model from the literature was coupled with an atomization multi-motion regime model. The model was validated against state-of-the-art ECN Spray G experiments for a constant-volume chamber under low evaporating condition. Then, the simulation of the spray injection in the engine was carried out and the achieved results were compared against the experimental data. Overall, good agreement between experiments and simulations was observed for the spray morphology and velocity fields in both cases. With reference to engine calculations the intake flow was seen to induce spray asymmetry. A partial vortex generated during the intake phase on the tumble plane interacts with the spray, developing into a full vortex which induces an upward flow that stabilizes the spray. The upward flows below the intake valve increase the dilution of the plume outside the tumble plane, which therefore exhibits reduced penetration. Moreover, the intake valves protect from the energetic intake flow the recirculation vortex generated at the tip of the plumes that lie outside the tumble plane. The intake flow helps fuse the vapor fuel clouds of the individual plumes near the injector tip, obtaining a vapor fuel with a shape like that generated by a horseshoe multi-hole injector. Finally, a phenomenological model of the interaction between the multi-hole injector jets and the engine intake flow was introduced to describe the spray evolution in a typical DISI engine.

Shock-less Hypersonic Intakes

The accuracy of CFD for simulating hypersonic air intake flow is verified by calculating the flow inside a Busemann type intake. The CFD results are then compared against the “exact” solution for the Busemann intake as calculated from the Taylor-McColl equations for conical flow. The method proposed by G. Emanuel (the Lens Analogy) for generating an intake shape that transforms parallel and uniform hypersonic (freestream) flow isentropically to another parallel and uniform, less hypersonic, flow has been verified by CFD (SOLVER II) simulation, based on Finite Volume Method (FVM). The shock-less (isentropic) nature of the Lens Analogy (LA) flow shapes has been explored at both on and off-design Mach numbers. The Lens Analogy (LA) method exhibits a limit line (singularity) for low Mach number flows, where the streamlines perform an unrealistic reversal in direction. CFD calculations show no corresponding anomalies.

Shock-less Hypersonic Intakes

The accuracy of CFD for simulating hypersonic air intake flow is verified by calculating the flow inside a Busemann type intake. The CFD results are then compared against the “exact” solution for the Busemann intake as calculated from the Taylor-McColl equations for conical flow. The method proposed by G. Emanuel (the Lens Analogy) for generating an intake shape that transforms parallel and uniform hypersonic (freestream) flow isentropically to another parallel and uniform, less hypersonic, flow has been verified by CFD (SOLVER II) simulation, based on Finite Volume Method (FVM). The shock-less (isentropic) nature of the Lens Analogy (LA) flow shapes has been explored at both on and off-design Mach numbers. The Lens Analogy (LA) method exhibits a limit line (singularity) for low Mach number flows, where the streamlines perform an unrealistic reversal in direction. CFD calculations show no corresponding anomalies.

Fan-Intake Coupling With Conventional and Short Intakes

The current trend in civil engine fans towards lower pressure ratio and larger diameter is accompanied by a need to shorten the engine intake length to reduce weight and drag. This paper uses full-annulus, unsteady CFD simulations of two coupled fan-intake configurations to explain the impact of flow field coupling and intake length on fan and intake performance. On-design and off-design operating points are considered at cruise and high angle of attack, respectively. The fan efficiency at cruise is shown to be determined by a trade-off between two effects. Cruise efficiency is reduced by 0.11% with a short intake due to increased potential flow field distortion, which alters the incidence and diffusion of the rotor. This is partially offset by a reduction in casing boundary layer thickness due to lower intake wetted area. At high angle of attack conditions, a short intake leads to increased potential flow field distortion and an earlier onset of intake flow separation due to a higher adverse pressure gradient approaching the fan. Both effects combine to reduce the fan thrust at such conditions, although the fan is shown to remain stable at attack angles up to 35°. The reduction in performance is shown to be dominated by flow separations in the rotor, which increase in size and severity for a given attack angle as the intake length is decreased. The fan is also shown to have a stronger influence on the form of the intake flow field in a short intake, suggesting that it is necessary to model the fan in the intake design process for a successful design.

How Different Snacks Produce a Distinct Effect in Salivary Protein Composition

Saliva secretion changes in response to different stimulation. Studies performed in animals and humans suggest that dietary constituents may influence saliva composition, although the dynamics of these changes, and how they are specific for each type of food, are little known. The objective of the present study was to access the short-term effects of different foods in salivation and salivary protein composition. Twelve participants were tested for four snacks (yoghurt, bread, apple and walnuts). Non-stimulated saliva was collected before and at 0′, 5′ and 30′ after each snack intake. Flow rate, total protein, alpha-amylase enzymatic activity and salivary protein profile were analyzed. Yoghurt and apple were the snacks resulting in higher salivary changes, with higher increases in flow rate and alpha-amylase activity immediately after intake. The expression levels of immunoglobulin chains decreased after the intake of all snacks, whereas cystatins and one pink band (proline-rich proteins—PRPs) increased only after yoghurt intake. Walnut’s snack was the one resulting in lower changes, probably due to lower amounts eaten. Even so, it resulted in the increase in one PRPs band. In conclusion, changes in saliva composition varies with foods, with variable changes in proteins related to oral food processing and perception.