scholarly journals Aerodynamic Performance of a Coaxial Hex-Rotor MAV in Hover

Aerospace ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 378
Author(s):  
Yao Lei ◽  
Jiading Wang ◽  
Wenjie Yang
Keyword(s):  
Performance Optimization ◽  
Structural Design ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Field Analysis ◽  
Test Results ◽  
Compact Structure ◽  
Coaxial Rotor ◽  
Optimum Aerodynamic ◽  
Flow Field Analysis

Micro aerial vehicles (MAVs) usually suffer from several challenges, not least of which are unsatisfactory hover efficiency and limited fly time. This paper discusses the aerodynamic characteristics of a novel Hex-rotor MAV with a coaxial rotor capable of providing higher thrust in a compact structure. To extend the endurance during hover, flow field analysis and aerodynamic performance optimization are conducted by both experiments and numerical simulations with different rotor spacing ratios (i = 0.56, 0.59, 0.63, 0.67, 0.71, 0.77, 0.83, 0.91). The measured parameters are thrust, power, and hover efficiency during the experiments. Retip ranged from 0.7 × 105 to 1.3 × 105 is also studied by Spalart–Allmaras simulations. The test results show that the MAV has the optimum aerodynamic performance at i = 0.56 with Retip = 0.85 × 105. Compared to the MAV with i = 0.98 for Retip = 0.85 × 105, thrust is increased by 5.18% with a reduced power of 3.8%, and hover efficiency is also improved by 12.14%. The simulated results indicate a weakness in inter-rotor interference with the increased rotor spacing. Additionally, the enlarged pressure difference, reduced turbulence, and weakened vortices are responsible for the aerodynamic improvement. This provides an alternative method for increasing the MAV fly time and offers inspiration for future structural design.

Optimized Shroud Design for Axial Turbine Aerodynamic Performance

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
L. Porreca ◽  
A. I. Kalfas ◽  
R. S. Abhari
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Field Analysis ◽  
Test Cases ◽  
Axial Turbine ◽  
Significant Difference ◽  
Flow Field Analysis ◽  
The Impact ◽  
Partial Shroud

This paper presents a comprehensive study of the effect of shroud design in axial turbine aerodynamics. Experimental measurements and numerical simulations have been conducted on three different test cases with identical blade geometry and tip clearances but different shroud designs. The first and second test cases are representative of a full shroud and a nonaxisymmetric partial shroud geometry while the third test case uses an optimized partial shroud. Partial shrouds are sometimes used in industrial application in order to benefit from the advantage of shrouded configuration, as well as reduce mechanical stress on the blades. However, the optimal compromise between mechanical considerations and aerodynamic performances is still an open issue due to the resulting highly three-dimensional unsteady flow field. Aerodynamic performance is measured in a low-speed axial turbine facility and shows that there are clear differences between the test cases. In addition, steady and time resolved measurements are performed together with computational analysis in order to improve the understanding of the effect of the shroud geometry on the flow field and to quantify the sources of the resultant additional losses. The flow field analysis shows that the effect of the shroud geometry is significant from 60% blade height span to the tip. Tip leakage vortex in the first rotor is originated in the partial shroud test cases while the full shroud case presents only a weak indigenous tip passage vortex. This results in a significant difference in the secondary flow development in the following second stator with associated losses that varies by about 1% in this row. The analysis shows that the modified partial shroud design has improved considerably the aerodynamic efficiency by about 0.6% by keeping almost unchanged the overall weight of this component, and thus blade root stresses. The work, therefore, presents a comprehensive flow field analysis and shows the impact of the shroud geometry in the aerodynamic performance.

scholarly journals Morphing Winglet Design for Aerodynamic Performance Optimization of the CRJ-700 Aircraft. Part 1 – Structural Design

2021 ◽  
Vol 13 (4) ◽  
pp. 113-128
Author(s):  
Paul MEYRAN ◽  
Hugo PAIN ◽  
Ruxandra Mihaela BOTEZ ◽  
Jeremy LALIBERTÉ
Keyword(s):  
Performance Optimization ◽  
Structural Design ◽  
Structural Model ◽  
Aerodynamic Performance ◽  
Structural Components ◽  
Transport Aircraft ◽  
Aerodynamic Loads ◽  
Load Factors ◽  
Morphing Technology ◽  
Maximum Stresses

This study aims to design a morphing winglet structure for the CRJ-700 regional transport aircraft. The morphing technology is applied on winglets to demonstrate a significant increase of the aerodynamic performance of aircraft. From the aerodynamic data of the LARCASE Virtual Research Simulator VRESIM, the aerodynamic benefits in the cruising phase were obtained through a study on the ParaView software. The morphing winglet design was drawn using CATIA V5; this new concept included several structural components, as well as a simple and light mechanism allowing to orientate the winglet angles between 90° and -90° of inclination. The structural model was exported to HyperMesh structural analysis software. Maximum stresses were obtained, and the model demonstrated its resistance to maximum aerodynamic loads as well as load factors of -2G to 7G.

Separation System Design and Equipments Performance Optimization for High-Viscosity and High-Density Drilling Fluid

2010 ◽  
Author(s):  
Renbo Xu ◽  
Jingjiang Deng ◽  
Xiaoguang Liu
Keyword(s):  
Performance Optimization ◽  
Orthogonal Experiment ◽  
Drilling Fluid ◽  
High Viscosity ◽  
High Density ◽  
Field Analysis ◽  
Operating Variables ◽  
Structural Variables ◽  
Orthogonal Experiment Method ◽  
Flow Field Analysis

For degassing of high-density and high-viscosity drilling fluid used in Ultra-high pressure oil & gas zones, carry out vertical separation systems, gravity separator for first and active centrifugal separator for secondary. Orthogonal experiment method for CFD simulates the flow field, Analysis operating variables, structural variables impact of efficiency; carry out the performance optimization scheme in accordance with the characteristics of flow fields.

Optimized Shroud Design for Axial Turbine Aerodynamic Performance

2007 ◽  
Author(s):  
L. Porreca ◽  
A. I. Kalfas ◽  
R. S. Abhari
Keyword(s):  
Flow Field ◽  
Aerodynamic Performance ◽  
Field Analysis ◽  
Test Case ◽  
Test Cases ◽  
Axial Turbine ◽  
Significant Difference ◽  
Flow Field Analysis ◽  
The Impact ◽  
Partial Shroud

This paper presents a comprehensive study of the effect of shroud design in axial turbine aerodynamics. Experimental measurements and numerical simulations has been conducted on three different test cases with identical blade geometry and tip clearances but different shroud designs. The first and the second test cases are representative of a full shroud and a non-axisymmetric partial shroud geometry while the third test case however uses an optimized partial shroud. Partial shrouds are sometimes used in industrial application in order to benefit from the advantage of shrouded configuration as well as reducing mechanical stress on the blades. However, the optimal compromise between mechanical considerations and aerodynamic performances is still an open issue due to the resulting highly 3-dimensional unsteady flow field. Aerodynamic performance is measured in a low-speed axial turbine facility and shows that there are clear differences between the test cases. In addition, steady and time resolved measurements are performed together with computational analysis in order to improve understanding of the effect of the shroud geometry on the flow field and to quantify the sources of the resultant additional losses. The flow field analysis shows that the effect of the shroud geometry is significant from 60% blade height span to the tip. Tip leakage vortex in the first rotor is originated in the partial shroud test cases while the full shroud case present only a weak indigenous tip passage vortex. This results in a significant difference in the secondary flow development in the following second stator with associated losses that varies of about 1% in this row. The analysis shows that the modified partial shroud design has improved considerably the aerodynamic efficiency of about 0.6% by keeping almost unchanged the overall weight of this component and thus blade root stresses. The work therefore presents a comprehensive flow field analysis and the shows the impact of the shroud geometry in the aerodynamic performance.

Sign in / Sign up

Export Citation Format

Share Document