Flow control valve

A flow control valve for high temperature fluids is disclosed. The valve is characterized by an all-metal flow control unit including a tubular conduit, terminating in a valve seat, a throttling cone having an internal, truncated conical surface coaxially related to the valve seat and supported for axial motion relative to the seat, and an axially reciprocable, flow-control plug supported in coaxial relation with the cone. The plug is provided with a truncated conical surface configured to be mated with the surface of the throttling cone for regulating a flow of fluid established through the unit and a curved shut-off surface

Flow Control Applications

Flow control has a long history with many successes across a plethora of applications. This report addresses the characteristics of the approaches that are actually used, why they are used, the many approaches that are not used, and why. Analysis indicates ways forward to increase applicability/usefulness, and efficiency of flow control research. Overall, greater and more effective progress in flow control requires utilization of far more detailed information early in the research process regarding application details and requirements

Flow Control: How New Geo-Economic Ambitions Reshape Globalization

Stewarding companies through a fragile International system in transition is and will be challenging. The current International order is fragile because the global leadership vacuum is widening, diverging concepts of sovereignty are colliding, the fabric of political power is changing, and emerging status quo challengers are combining cooperation and competition to test the resolve of incumbent lead nations. The ambivalence of technological progress reinforces all of these aspects. Most importantly, corporate decision-makers and investors need to understand that Adam Smith's idea of an 'invisible hand' driving a laissez-faire approach to politics is over. This transition phase is characterized – proverbially – by the 'iron fist with deep pockets,' i.e., authoritarian capitalism, and the vociferous 'Twitter finger,' i.e., executive populism. Both question well-established modes of interaction between politics and economics

Fluid flow control value Patent

Fluid flow control valve for regulating fluids in molecular quantitie

Supersonic laminar-flow control

Detailed, up to date systems studies of the application of laminar flow control (LFC) to various supersonic missions and/or vehicles, both civilian and military, are not yet available. However, various first order looks at the benefits are summarized. The bottom line is that laminar flow control may allow development of a viable second generation SST. This follows from a combination of reduced fuel, structure, and insulation weight permitting operation at higher altitudes, thereby lowering sonic boom along with improving performance. The long stage lengths associated with the emerging economic importance of the Pacific Basin are creating a serious and renewed requirement for such a vehicle. Supersonic LFC techniques are discussed

Power Flow Control and Current Ripple Minimization of HVDC Converter System by Using Zero-Sequence Voltage Injection Control

This paper introduces the Zero_Sequence Voltage_Injection(ZSVI) based Model Predictive_Control (MPC) to minimize the ripples in dc current & voltage and concurrently regulate the power_flow & dc_current. This paper takes the benefits to calculate and inject best possible zero_sequence_voltage_components to Parallel_Hybrid Modular Multilevel_Converter (PHMMC) dc bus voltage. Dc line current has been derived by discrete_time_dynamic model and also it expands the predictive_model. Required amount of zero sequence voltage is injected to reference voltage of dc bus by using predictive model. Compared to triplen_harmonic injection_method, the proposed scheme improves the PHMMC_performance by minimizing the ripples of dc_voltage ¤t. Execution of the proposed methodology of PHMMC-based HVDC system is done using SIMULINK/MATLAB

Electrohydrodynamic Methods for Fluid Flow Control

No abstract available

Stability analysis of slug flow control

The threat of slugging to production facilities has been known since the 1970s. This undesirable flow phenomenon continues to attract the attention of researchers and operators alike. The most common method for slug mitigation is by choking the valve at the exit of the riser which unfortunately could negatively affect production. The focus, therefore, is to satisfy the need for system stability and to maximize production simultaneously. Active feedback control is a promising way to achieve this. However, due to the complexity of multiphase flow systems, it is a challenge to develop a robust slug control system to achieve the desired performance using existing design tools. In this paper, a new general method for multiphase flow system stability analysis was proposed. Active feedback control was observed to optimize slug attenuation compared with manual choking. The use of soft sensors was believed to be desirable for the practical implementation of the proposed control technique

Queue Dynamics With Window Flow Control

This paper develops a new model that describes the queueing process of a communication network when data sources use window flow control. The model takes into account the burstiness in sub-round-trip time (RTT) timescales and the instantaneous rate differences of a flow at different links. It is generic and independent of actual source flow control algorithms. Basic properties of the model and its relation to existing work are discussed. In particular, for a general network with multiple links, it is demonstrated that spatial interaction of oscillations allows queue instability to occur even when all flows have the same RTTs and maintain constant windows. The model is used to study the dynamics of delay-based congestion control algorithms. It is found that the ratios of RTTs are critical to the stability of such systems, and previously unknown modes of instability are identified. Packet-level simulations and testbed measurements are provided to verify the model and its predictions

Fluid flow control with transformation media

We introduce a new concept for the manipulation of fluid flow around three-dimensional bodies. Inspired by transformation optics, the concept is based on a mathematical idea of coordinate transformations and physically implemented with anisotropic porous media permeable to the flow of fluids. In two situations - for an impermeable object placed either in a free-flowing fluid or in a fluid-filled porous medium - we show that the object can be coated with an inhomogeneous, anisotropic permeable medium, such as to preserve the flow that would have existed in the absence of the object. The proposed fluid flow cloak eliminates downstream wake and compensates viscous drag, hinting us at the possibility of novel propulsion techniques.Comment: 4 pages, 7 figure