Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

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A Simple Analytical Model to Simulate Oblique Ballistic Impact onto Fabric

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.3453 ◽

2011 ◽

Vol 110-116 ◽

pp. 3453-3458

Author(s):

Mohamad Ali Akbari ◽

Golam Hosein Liaghat ◽

Hadi Sabouri

Keyword(s):

Experimental Data ◽

Analytical Model ◽

Ballistic Impact ◽

Experimental Results ◽

Simple Analytical Model ◽

Good Agreement

A simple analytical model for oblique ballistic impact of projectiles into fabrics are presented. This model is extension of Chocron-Benloulo penetration model. Results are compared with experimental data. There is good agreement between analytical and experimental results.

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Liquid Container Filling and Charging

Journal of Engineering for Industry ◽

10.1115/1.3438979 ◽

1976 ◽

Vol 98 (2) ◽

pp. 730-732

Author(s):

R. H. Nunn ◽

E. J. Gibson

Keyword(s):

Closed Form ◽

Dynamic Behavior ◽

Analytical Model ◽

Experimental Results ◽

Simple Analytical Model ◽

Liquid Slug ◽

Analytical Formulation ◽

Closed Form Solutions

A simple analytical model has been developed to describe the dynamic behavior of a liquid slug as it is rapidly and suddenly rammed into a receiving chamber. Useful closed-form solutions are obtained from approximate versions of the governing relationships. Experimental results indicate the essential correctness of the analytical formulation.

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Theoretical Range and Trajectory of a Water Jet

Volume 7A: Fluids Engineering Systems and Technologies ◽

10.1115/imece2015-52103 ◽

2015 ◽

Cited By ~ 5

Author(s):

Ben Trettel ◽

Ofodike A. Ezekoye

Keyword(s):

Experimental Data ◽

Froude Number ◽

Analytical Model ◽

Droplet Size ◽

Fire Protection ◽

Potential Flow ◽

Water Jet ◽

Simple Analytical Model ◽

Qualitative Understanding ◽

Vertical Height

The trajectory of a water jet is important in many applications, including fire protection, irrigation, and decorative fountains. Increasing the maximum distance the jet travels by changing the nozzle or other variables is often desirable. This distance could be the horizontal range (also often called the reach or throw) or the maximum vertical height. Which factors control the trajectory are unclear. Consequently, a simple analytical model is developed which provides a qualitative understanding of the system. This model differs significantly from previous models. Previous models either used a dragless trajectory, which is correct according to potential flow theory if the jet does not break into droplets, or treated the trajectory as if droplets formed immediately upon leaving the nozzle. Both approaches have been noted to be unsatisfactory by past researchers. Our model compares favorably against available experimental data. Using our model, we show that the range decreases as the nozzle Froude number increases and that range increases as breakup length and droplet size increase.

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Modeling and Characterization of the Scratch Drive Actuator

Microelectromechanical Systems ◽

10.1115/imece2004-59908 ◽

2004 ◽

Cited By ~ 2

Author(s):

Jessica R. Bronson ◽

James J. Allen ◽

Gloria J. Wiens

Keyword(s):

Experimental Data ◽

Analytical Model ◽

Input Voltage ◽

Experimental Results ◽

Step Size

This paper presents the characterization of scratch drive actuators (SDAs) built using Sandia National Laboratories (SNL) SUMMiTTM V micromachining process. Experimental data is used to characterize the output step size as a function of input voltage. This data is correlated to an analytical model in an effort to better understand and predict the stepping motion of these devices. The experimental results match well with the predictions from the model. Experimental data shows that the step sizes are on the order of 10 nm, and force estimates show that one SDA is capable of producing forces in excess of 100 μN for each step.

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Cross Coupling in Parallel Kinematic MEMS Nanopositioners

Volume 3: Multiagent Network Systems; Natural Gas and Heat Exchangers; Path Planning and Motion Control; Powertrain Systems; Rehab Robotics; Robot Manipulators; Rollover Prevention (AVS); Sensors and Actuators; Time Delay Systems; Tracking Control Systems; Uncertain Systems and Robustness; Unmanned, Ground and Surface Robotics; Vehicle Dynamics Control; Vibration and Control of Smart Structures/Mech Systems; Vibration Issues in Mechanical Systems ◽

10.1115/dscc2015-9824 ◽

2015 ◽

Cited By ~ 1

Author(s):

Mohammad Maroufi ◽

S. O. Reza Moheimani

Keyword(s):

Experimental Data ◽

Analytical Model ◽

Close Agreement ◽

Cross Coupling ◽

Experimental Results ◽

Micro Fabrication ◽

Parallel Kinematic Mechanism ◽

Parallel Kinematic ◽

The Cross ◽

Kinematic Mechanism

In this paper we study the origins of the cross coupling phenomenon in MEMS nanopositioners with a parallel kinematic mechanism. An analytical model is provided for a generic 2-DOF MEMS nanopositioner. The model accounts for the potential mechanical asymmetries present in the device due to micro-fabrication imperfections. Simulations are performed based on the obtained model and compared with experimental data from a previously reported MEMS nanopositioner. A close agreement is observed between the analytical and experimental results, leading to a better understanding of the phenomenon.

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The Robustness of Honesty Effects on Budget Proposals when the Superior has Rejection Authority

The Accounting Review ◽

10.2308/accr-50937 ◽

2014 ◽

Vol 90 (2) ◽

pp. 467-493 ◽

Cited By ~ 47

Author(s):

Jeremy D. Douthit ◽

Douglas E. Stevens

Keyword(s):

Experimental Data ◽

Experimental Evidence ◽

Experimental Results ◽

Data Availability ◽

Budgetary Slack ◽

Participative Budgeting ◽

Budget Request ◽

Distributional Fairness

ABSTRACT Rankin, Schwartz, and Young (2008) find experimental evidence that manipulating whether the budget request of the subordinate requires a factual assertion has no effect on budgetary slack when the superior can reject the budget. This calls into question the role of honesty in participative budgeting settings. Using Rankin et al.'s (2008) manipulation to capture honesty effects, we examine the robustness of honesty effects on budget proposals when the superior has rejection authority in two experiments. In Experiment 1, we document that honesty has a strong effect on budgetary slack when the salience of distributional fairness is reduced by withholding the relative pay of the superior from the subordinate. In Experiment 2, we document that honesty continues to have a strong effect on budgetary slack when the salience of reciprocity is increased by giving the superior the ability to set the subordinate's salary. Thus, our evidence suggests that honesty effects on budget proposals are generally robust to giving the superior rejection authority. Our study helps explain prior experimental results and clarifies the role of honesty in participative budgeting settings. Data Availability: Experimental data are available from the authors upon request.

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A Simple Analytical Model to Simulate Textile Fabric Ballistic Impact Behavior

Textile Research Journal ◽

10.1177/004051759706700707 ◽

1997 ◽

Vol 67 (7) ◽

pp. 520-528 ◽

Cited By ~ 47

Author(s):

Isaias Sidney Chocron-Benloulo ◽

J. Rodríguez ◽

Vicente Sánchez-Gálvez

Keyword(s):

Composite Materials ◽

Analytical Model ◽

High Performance ◽

Predictive Power ◽

Ballistic Impact ◽

Experimental Results ◽

Impact Behavior ◽

Light Weight ◽

Simple Analytical Model ◽

Textile Fabric

Composite materials have become very attractive as personal and vehicle armors because of their light weight and high performance. Unfortunately, these materials are difficult to simulate numerically or analytically, and the only way to check their performance is experimentally. A first step could be the study of the primary components of the composite. The fabric is undoubtedly the most important one, and an analytical model of its behavior is developed in this paper. The model calculates residual velocities, velocity and strain in the fabric histories, and absorbed energies. The comparison with experimental results for Kevlar 29 and the application of the model to Dyneema are very satisfactory as a demonstration of the good predictive power of an analytical model that is easy to understand and easy to compute.

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ANALYTICAL MODEL FOR NON-SELF ALIGNED BURIED P-LAYER SiC MESFET

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156404003010 ◽

2004 ◽

Vol 14 (03) ◽

pp. 897-905 ◽

Cited By ~ 1

Author(s):

R. S. GUPTA ◽

SANDEEP KUMAR AGGARWAL ◽

RITESH GUPTA ◽

MRIDULA GUPTA ◽

SUBHASIS HALDAR

Keyword(s):

Experimental Data ◽

Analytical Model ◽

Excellent Agreement ◽

Small Signal ◽

Static Characteristics ◽

Signal Parameters ◽

Saturation Region ◽

Capacitance Voltage ◽

Layer 4

A new analytical model for saturation region is proposed for buried p-layer 4 H - SiC MESFET considering the effect of B.P. layer. This model provides the static characteristics, small signal parameters and is also extended to predict capacitance-voltage characteristics of the device. The results so obtained are in excellent agreement with experimental data confirming the validity of this model.

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