Flow quality improvement of the wind tunnel testing for a highly-loaded compressor cascade at high incidence

To obtain reliable and accurate experimental data in cascade testing, the influencing factors and the improving method of the flow quality of a highly-loaded compressor cascade under high incidence were investigated through a series of numerical simulations and experiments. The numerical method was validated by experimental data and agreed well at both incidence angles of 0° and 6°. Under the original upper end wall, both experimental and numerical results indicated an unsatisfactory flow quality of the cascade with an obvious nonuniformity of inlet Mach number, and the incidence of the central blade is 3.6° larger than the theoretical value. Using a small curved upper wall can reduce the severe flow separation on the upper wall and achieve a maximum improvement in flow quality under the critical installation angle, where the incidence deviation of the central blade was reduced to 2.1°. Using the combination of adjustable tailboards and a small curved upper end wall can further improve the cascade flow quality. Under the optimal angle of the tailboards, both the inflow uniformity and the outflow periodicity of the three middle blade passages the test requirements, and the incidence deviation of the central blade is reduced to 0.2°.

RESEARCH OF ARCHITECTURE FORMATION LANDSCAPE THEATERS IN UKRAINE

The article is devoted to the problems of landscape theaters architecture formation on the territory of Ukraine in the realities which have developed in the course of typology development and an arrangement of the cultural data and entertaining and leisure establishments in modern conditions. The article examines the specifics of the landscape theaters location depending on the functional purpose, capacity of the auditorium and attendance level of various theatrical performances in the open air in Ukraine. Based on the results of professional questionnaires and analysis of statistical data on the theater and concert network in Ukraine, the author proposes 15 factors that shape the modern architecture of Ukrainian landscape theaters. The author investigates how these factors modify the spectator environment and shows the tools and techniques that allow you to create a harmonious space of the theater. The list of the above factors influencing the formation of the landscape theaters architecture in Ukraine should include such factors as: the capacity of the auditorium; functional purpose of the building; location of the theater; the mode of the auditorium openness and stage; special conditions of the open-air theater location zone. In addition, the author investigates the following factors in the formation of landscape theaters architecture, such as: organizational schemes of the stage; the configuration of the amphitheater in relation to the stage; ways to evacuate visitors from the auditorium in case of emergencies; determination of the optimal angle of the auditorium; architectural and constructive solution of the theater location (on a natural or anthropogenic basis). The author analyzes the influence on the formation of the landscape theaters architecture due to the system of the stage layout and arrangement; when using special technological techniques and technical means; by considering the mobility of the theater; under the conditions of synthesis at the location of the stage relative to the spectator amphitheater; using the means of green architecture and design solutions in the organization of theater space.

Effect of the attack angle of the ribs on the flow and heat transfer in a flat channel

The results of numerical simulation of a turbulent flow in a flat channel with periodic inclined ribs by the RANS method are presented. The Reynolds number, calculated from the rib height and the superficial velocity, is Re = 12600. The obtained data are analyzed in order to determine the influence of the inclination angle on heat transfer. It is shown that the optimal angle of inclination, at which the average heat transfer in the channel is maximum, is 60°.

A Convenient Way to Determine the Optimum Angle of Incidence of Fizeau Interferometer

In a Fizeau interferometer, off-axis illumination will lead to fringe optimization. Primarily due to the unique structure of our interferometer, we first analyze the influence of the optical properties of the parallel plate as a part of the interferometer on the optimal incident angle. Generally, the incident angle determination is mainly based on the graphing method proposed by Langenbeck and the estimation formula proposed by Kajava. However, Langenbeck’s method is cumbersome, and the error of Kajava’s estimation formula is large. Based on the predecessors, this paper proposes a modified method of determining the optimal angle of incidence and further derives more accurate optimal angle expressions than Kajava’s. By simply substituting the wedge angle of the wedge cavity and the reflectivity of the cavity, the optimum incidence angle can be obtained immediately. Thus, it eliminates the tedious and complex process of finding the optimum incident angle by graphing method and makes the formula method the simplest method to find the optimum incident angle. Finally, the comparison of the interference intensity at the optimum incidence angle calculated by the improved method and normal incidence is given. It is found that the beam has a good suppression effect on the sub-peak when it is incident at the optimum incident angle calculated by the method in this paper.

RE-EVALUATION OF THE EGYPTIAN CODE OF HOUSING AND ENERGY CONSUMPTION WITH EMPHASIS ON SHADING DEVICES ROTATION ANGLES

The passive system technique is dynamically used as an alternative to the active system, in order to minimize the peak loads and the total EUI in kWh/ m2 for any building prototype. Sun breaker or shading device is a basic traditional method and Mashrabiya previously used for privacy and reduces the heat gained and emitted from sun`s rays, in addition to the fabricated wood material and its specs of bad conductor. the study aims to investigate the effect of rotational shading devices around the y-axis, will the rotation have a significant impact on the EUI or not? The research methodology is built upon generative modeling tool of parametric design, Rhinoceros Version 6.0, with the cooperation of Grasshopper, Ladybug& Honeybee, and Toolbox. Five hundred running simulations are carried out to determine the optimal angle of rotation with maximum reduction in cooling loads, and the interpretation is 30°. Two linear regression equations are derived out of this valuable study to deduce the correlation between independent and dependent variables when the sun breaker material is matt or reflective, and how the total EUI kWh/m2 can be minimized?

Performance investigation of grid-connected photovoltaic systems for family household: A case study in Amman, Jordan

The main objective of the paper is to investigate the feasibility of small-scale grid-connected PV systems with various PV technologies (mono-crystalline silicon and poly-crystalline silicon) and sun-tracking modes including fixed tilt and 2-axis systems for rooftop households in Amman, Jordan. A case study is applied to Al Jama’a and Abu Nusir, Amman, Jordan. Typical households were chosen for this region to establish a load profile according to monthly electrical bills. The results show that the annual electrical energy from fixed small-scale PV panels tilted at an optimal angle was ranged from 3499.04kWh to 8811.62kWh, while the annual electrical energy from the PV tracking system was within the range of 4788.05-12128.30kWh. This amount of energy output would contribute significantly to reduce fossil fuel consumption and CO2 emissions in the country. Moreover, it is found that the highest energy consumption can be covered by PV systems is recorded in winter. Also, the average energy production cost is ranged from 0.0444-0.0530$/kWh for all proposed systems based on the financial assumptions used in this study. It is concluded that the small-scale grid-connected rooftop PV systems are found to be economically justifiable.

Lift and Drag Coefficient Map of NACA4415 Airfoil

The NACA4415 airfoil was numerically simulated with the help of the Fluent software to analyze its aerodynamic characteristics. Results are acquired as follows: The calculation accuracy of Fluent software is much higher than that of XFOIL software; the calculation result of SST k-ω(sstkw) turbulence model is closest to the experimental value; within a certain range, the larger the Reynolds number is, the larger the lift coefficient and lift-to-drag ratio of the airfoil will be, and the smaller the drag coefficient will be; when the angle of attack is less than the optimal angle of attack, the Reynolds number has less influence on the lift-to-drag coefficient and the lift-to-drag ratio; as the Reynolds number increases, the optimal angle of attack increases slightly, and the applicable angle of attack range for high lift-to-drag ratios becomes smaller.

Analysing an Optimal Angle in Basketball Free Throw

Basketball is a sport, played worldwide by people of all ages, from young to old. The most important skill that a football player should have is shooting. Shooting the ball into the hoop involves projectile motion. The ability of a player to shoot will determine the scores of his/her team. The angle and initial velocity taken during the shooting, plays a vital role, so that a perfect shooting could be achieved. This work has been conducted to determine the optimal throwing angle and initial velocity that a player should take in order to get the best shooting. The relationship of these factors were investigated: the throwing angle and player’s height, initial velocity with the player’s height, as well as the throwing angles versus time taken for the ball to reach the hoop. Our focus is to maximize the height of the ball, before it is thrown. Newton’s law and the concept of projectile motion were applied using a calculus-based model. Relationship between the player’s height with the initial velocity, optimal throwing angle and time taken for the ball to reach the hoop were discussed. Perfect optimal release angle were determined for thirty data of NBA players. It shows that the player’s height is inversely proportional to the initial velocity and the optimal throwing angle. The obtained results also concluded that the optimal throwing angle is directly proportional to the time taken for a ball to reach its maximum height.