k. divsalar

This work presents a numerical Simulation of an underwater glider to investigate the effect of angle of attack on the hydrodynamic coefficients such as lift, drag, and torque. Due to the vital role of these coefficients in designing the controllers of a glider, and to obtain an accurate result, this simulation has been carried on at a range of operating velocities. The total length of the underwater glider with two wings is 900 mm with a 4-digits NACA0009 profile. The fluid flow regime is discretized and solved by computational fluid dynamics and finite volume method. Since the Reynolds number range for this study is in a turbulent flow state (up to 3.7e06), the κ-ω SST formulation was used to solve Navier-Stokes equations and continuity and the angles of attack ranging are from - 8 to 8 degrees. The main purpose of this research is to study the effect of each of the dynamics parameters of glider motion such as velocity and angle of attacks on the hydrodynamic coefficients. Based on the results, the drag and lift coefficients are enhanced with increasing the angle of attack. In addition, the drag coefficient enhanced with increasing the velocity however, when the glider velocity is increased, the lift coefficient does not change significantly except at the highest angle of attack that decreases. The highest drag coefficient is 0.0246, which corresponds to the angle of attack of -8 and the Reynolds number of 3738184. In addition to simple geometry, the glider studied in this paper shows relatively little resistance to flow.

In order to control seagliders dynamic motion, the full recognition of the hydrodynamic forces affecting their motion is very important. In this paper, the dynamic motion of a seaglider with a spherical nose has been studied and evaluated by using a developed computer code to obtain the hydrodynamics forces. Based on this algorithm, the time when the seaglider dives into the water until it returns to the water surface, as well as the parameters affecting the seaglider motion were investigated. Also, using a meta-heuristic optimization algorithm, the parameters affecting the optimal performance of the glider were determined. The investigated parameters include diving speed, diving angle, wing angle, distance and position of the seaglider center of mass relative to the center of buoyancy (center of the coordinate system). The speed varies from 0.5 to 5 m/s, the diving angle includes 15, 30, 45 and 60 degree, the wing angle includes 0, 5, 10, 15 and 20 degree and the distance between the center of mass and the center of buoyancy is assumed to be 0, 1, 3 and 5 cm. According to the results, the diving angle of 30°, the wing angle of 5° and the center of mass and the center of buoyancy distance of zero and 1 cm at the diving speed of 5 m/s were selected as optimal values.

Menopause is one of the most sensitive events in a woman's life. Health improvement in this period can bring women a better quality of life and has many effects. This study was conducted to investigate the relationship between the level of physical activity and the level of health of postmenopausal women in Kerman Province.

A total of 536 postmenopausal women were selected from Kerman province. The Goldberg’s General Health Questionnaire was used to measure the level of health and the general physical activity questionnaire (GPAQ) was applied to determine the amount of physical activity. The formula for measuring body mass index was used for BMI. Ultimately, the Spearman, Kruskal Wallis, and Bonferroni statistics were used because the data distribution was not normal.

The amount of physical activity in postmenopausal women in Kerman Province was lower than the WHO recommended. There was a significant relationship between physical activity with the level of health (r = 259), (P≤0.001). Moreover, BMI and health level had an inverse relationship (-0.186) (P≤0.001).

Based on the results, a significant relationship was found between physical activity and general health status of postmenopausal women. Considering the effect of physical activity on health, it can be concluded that increased physical activity of postmenopausal women in Kerman Province can improve their health and BMI.