Blunt body wave drag reduction by means of a standoff spike

2001 ◽  
Author(s):  
Yair Guy ◽  
Thomas McLaughlin ◽  
Julie Morrow
Keyword(s):  
Drag Reduction ◽  
Blunt Body ◽  
Body Wave ◽  
Wave Drag ◽  
Wave Drag Reduction

Blunt-body wave drag reduction using focused energy deposition

AIAA Journal ◽  
1999 ◽  
Vol 37 ◽  
pp. 460-467 ◽  
Author(s):  
David Riggins ◽  
H. F. Nelson ◽  
Eric Johnson
Keyword(s):  
Drag Reduction ◽  
Energy Deposition ◽  
Blunt Body ◽  
Body Wave ◽  
Wave Drag ◽  
Wave Drag Reduction

Blunt-Body Wave Drag Reduction Using Focused Energy Deposition

AIAA Journal ◽  
10.2514/2.756 ◽  
1999 ◽  
Vol 37 (4) ◽  
pp. 460-467 ◽  
Author(s):  
David Riggins ◽  
H. F. Nelson ◽  
Eric Johnson
Keyword(s):  
Drag Reduction ◽  
Energy Deposition ◽  
Blunt Body ◽  
Body Wave ◽  
Wave Drag ◽  
Wave Drag Reduction

A numerical study on the single pulsed energy addition based unsteady wave drag reduction at varied hypersonic flow regimes

2020 ◽  
pp. 095441002097313
Author(s):  
Dathi SNV Rajasekhar Rao ◽  
Bibin John
Keyword(s):  
Steady State ◽  
Mach Number ◽  
Drag Reduction ◽  
Shock Layer ◽  
Blunt Body ◽  
Wave Drag ◽  
Flow Features ◽  
Energy Pulse ◽  
Energy Addition ◽  
Wave Drag Reduction

In this study, unsteady wave drag reduction in hypersonic flowfield using pulsed energy addition is numerically investigated. A single energy pulse is considered to analyze the time-averaged drag reduction/pulse. The blast wave creation, translation and its interaction with shock layer are studied. As the wave drag depends only on the inviscid aspects of the flowfield, Euler part of a well-established compressible flow Navier-Stokes solver USHAS (Unstructured Solver for Hypersonic Aerothermodynamics) is employed for the present study. To explore the feasibility of pulsed energy addition in reducing the wave drag at different flight conditions, flight Mach numbers of 5.75, 6.9 and 8.0 are chosen for the study. An [Formula: see text] apex angle blunt cone model is considered to be placed in such hypersonic streams, and steady-state drag and unsteady drag reductions are computed. The simulation results indicate that drag of the blunt-body can be reduced below the steady-state drag for a significant period of energy bubble-shock layer interaction, and the corresponding propulsive energy savings can be up to 9%. For energy pulse of magnitude 100mJ deposited to a spherical region of 2 mm radius, located 50 mm upstream of the blunt-body offered a maximum percentage of wave drag reduction in the case of Mach 8.0 flowfield. Two different flow features are found to be responsible for the drag reduction, one is the low-density core of the blast wave and the second one is the baroclinic vortex created due to the plasma energy bubble-shock layer interaction. For the same freestream stagnation conditions, these two flow features are noted to be very predominant in the case of high Mach number flow in comparison to Mach 5.75 and 6.9 cases. However, the ratio of energy saved to the energy consumed is noted as a maximum for the lower Mach number case.

scholarly journals Effects of Heat Addition on Wave Drag Reduction of a Spiked Blunt Body

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hongyu Wang ◽  
Yanguang Yang ◽  
Langquan Li ◽  
Gang Wang ◽  
Qinghu Zhang
Keyword(s):  
Drag Reduction ◽  
High Speed ◽  
Blunt Body ◽  
Wave Drag ◽  
The Body ◽  
Continuous Heating ◽  
Heat Addition ◽  
Reduction Coefficient ◽  
Wave Drag Reduction ◽  
High Speed Vehicle

Drag reduction technology plays a significant role in extending the flight range for a high-speed vehicle. A wave drag reduction strategy via heat addition to a blunt body with a spike was proposed and numerically validated. The heat addition is simulated with continuous heating in a confined area upstream of the blunt body. The effects of heat addition on drag reduction in three flow conditions ( M = 3.98 , 5 , 6 ) were compared, and the influence of power density q h ( q 1 = 2.0 × 10 8   W / m 3 , q 2 = 5.0 × 10 8   W / m 3 , and q 3 = 1.0 × 10 9   W / m 3 ) of heating was evaluated. Results show that the heat addition has a positive way to reduce the drag of the body with a spike alone, and more satisfactory drag reduction effectiveness can be achieved at a higher Mach number. The drag reduction coefficient increases with q h in the same flow condition, with a maximum of 38.9% ( M = 6 ) as q 3 = 1.0 × 10 9   W / m 3 . The wave drag reduction principle was discussed by a transient calculation, which indicates that the separation region has entrainment of the heated air and expanded with its sonic line away from the blunt cone, which results in an alleviation of the pressure load caused by shock/shock interaction.

Drag Reduction Performance due to Repetitive Laser Pulses on the Blunt Body

2011 ◽  
Author(s):  
Jae-Hyung Kim ◽  
Akihiro Sasoh
Keyword(s):  
Drag Reduction ◽  
High Speed ◽  
Energy Deposition ◽  
Blunt Body ◽  
Laser Pulses ◽  
Wave Drag ◽  
Force Balance ◽  
Balance System ◽  
Convex Lens ◽  
Wave Drag Reduction

Supersonic wave drag reduction due to the repetitive laser induced energy deposition is performed experimentally in this study. Laser pulses are irradiated through a convex lens installed in side of the in-draft wind tunnel of Mach 1.94. The maximum frequency and power of the energy deposition is limited up to 50kHz and 400W. In order to estimate the drag reduction, time-averaged drag force is measured by a force balance system and stagnation pressure history is synchronized with corresponding sequential schlieren images captured by high-speed camera. Drag reduction performance is linearly increased up to 21% with input laser power. The power gain which only depends on the pulse energy, is realized by approximately 7. Virtual spike formation induced by highrepetitive energy depositions is remarkably discussed in the visualization results.

Supersonic wing-body wave drag co-ordinated optimisation based on FCE methodology

2014 ◽  
Vol 118 (1209) ◽  
pp. 1359-1372
Author(s):  
X. Guan
Keyword(s):  
Drag Reduction ◽  
Body Wave ◽  
Aerodynamic Performance ◽  
Wave Drag ◽  
Cruise Missile ◽  
Shape Transformation ◽  
Wave Drag Reduction ◽  
Drag Ratio ◽  
Cruise Flight ◽  
Lift To Drag Ratio

Abstract Wave drag reduction is important for the aerodynamic performance optimisation of supersonic cruise aircrafts, such as the supersonic civil transport and the supersonic cruise missile. In this paper a method of the supersonic wing-body wave drag optimisation, the wave drag co-optimisation based on far-field composite elements (CoFCE), is proposed based on class-shape-transformation (CST) parameterisation. Wave drag optimisation cases of a supersonic civil transport wing-body are presented, including the optimisation results and computation cost analyses. It is suggested that the supersonic wing-body wave drag can be significantly reduced by the proposed method with relatively small numbers of design parameter. In the optimisation case presented in this paper a 45% wave drag reduction is achieved. The wave drag optimised configuration also achieved significant lift to drag ratio improvements in small angles-of-attack supersonic cruise flight conditions.

DYNAMICS OF COUNTER-FLOW INJECTION FOR WAVE DRAG REDUCTION

2018 ◽  
Author(s):  
Vishnu Prakash K ◽  
Siddesh Desai ◽  
Hrishikesh Gadgil ◽  
Vinayak Kulkarni
Keyword(s):  
Drag Reduction ◽  
Flow Injection ◽  
Wave Drag ◽  
Counter Flow ◽  
Wave Drag Reduction

Supersonic Bi-Directional Flying Wing Wave Drag Optimization Based on Alternative Form of CST Method

2013 ◽  
Vol 477-478 ◽  
pp. 240-245
Author(s):  
Xiaohui Guan
Keyword(s):  
Drag Reduction ◽  
High Speed ◽  
Wave Drag ◽  
Alternative Form ◽  
Shape Transformation ◽  
Flat Bottom ◽  
Symmetric Configuration ◽  
Shape Parameterization ◽  
Wave Drag Reduction ◽  
Sufficient Precision

Bi-directional Flying Wing (BFW) is a new supersonic civil transport shape concept that aims to meet the conflict requirements of high speed cruise and low speed take-off/landing missions. In this paper the Class-Shape-Transformation (CST) shape parameterization method is modified to represent the BFW shape, and new basis functions suitable for the BFW airfoil representation are constructed. The Far-field Composite Element (FCE) wave drag optimization is performed on both the flat bottom and symmetric BFW configurations, and the drag reduction effects and result precision are surveyed. It is suggested that significant wave drag reduction can be achieved by the FCE optimization for both the flat bottom and the symmetric BFW configurations. The wave drag coefficients with sufficient precision can be obtained in the FCE optimization of the symmetric configuration; while the FCE optimization results of the flat bottom one are not accurate enough.

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