On the aerodynamic characteristics of thin slab delta wings at hypersonic speeds — part 1: interference of lee side bodies

Ramesh, Ranjini Garani; Ramaswamy, MA; Vasudevan, Balamurali; Prabhu, A.

doi:10.1017/s0001924000017917

Cited by 4 publications

(3 citation statements)

References 7 publications

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“…The uncertainty analyses for the experimental data were done using the method of Kline and McClintock [19]. They are reported in [16,[20][21][22] and the interested reader is requested to refer to them.…”

Section: Resultsmentioning

confidence: 99%

“…The results regarding the effect of the interference of the lee-side body on the longitudinal aerodynamic characteristics of a thin slab delta wing for the case of the 76 • wing with t/c = 0.053 are presented here. Results for various sweeps and various lee-side bodies are presented in [16,20,21] and the interested reader may refer to them for further details.…”

Section: Interference Of Lee-side Bodiesmentioning

confidence: 99%

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Thin flat balances for testing thin delta wings at hypersonic speeds

Ramesh¹

2001

Meas. Sci. Technol.

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This paper concerns the design and development of two special novel thin internal strain gauge balances for testing thin slab delta wings at hypersonic speeds. Of the two balances, one is a thin three-component balance and the other is a thin six-component balance. Unlike the conventional balances, which are circular in cross section, the balances discussed here are flat and have rectangular cross sections. Here, the design philosophy and the metallic architecture of these balances are discussed in detail. This paper is divided into three parts wherein the first part deals with the thin three-component balance the second part addresses the thin six-component balance and, in the third part, typical results obtained using these two balances are presented. The thin three-component balance has a thickness of 2.5 mm and can be housed inside a wing as thin as 6 mm. Because of its thinness, the axial output exhibited non-linear interaction from the normal force loading. Hence, combined loading is performed. In order to deduce the second-order coefficients, a new method has been proposed and a comparison with the existing method shows that this is better than the previous method. This balance has been used to generate aerodynamic data on thin slab delta wings with and without lee-side balance housing bodies. In this way, it is demonstrated that the lee-side bodies do interfere even when they come into the aerodynamic shadow of the wing. The thin six-component balance has a thickness of 4 mm and can be housed inside an 8 mm thick wing. Although this balance is also thin, it exhibited excellent linearity in all the bridges. In spite of this, it is subjected to several possible combinations of combined loading and the `work back' loads are calculated using the linear coefficients. The work back loads agree very well with the applied loads. Hence, linear coefficients have been used for the purpose of data reduction. The effects of flap deflection on the aerodynamic characteristics of thin slab delta wings have been studied using this balance. All the experiments were conducted at Mach 8.2 and a Reynolds number of 2.13×106.

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Section: Resultsmentioning

confidence: 99%

Section: Interference Of Lee-side Bodiesmentioning

confidence: 99%

Thin flat balances for testing thin delta wings at hypersonic speeds

Ramesh¹

2001

Meas. Sci. Technol.

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“…Also, the facility contributed significantly to academic programs leading to several doctoral and masters degree students performing original research in this field. Pioneering work in the design of miniaturized balances led to outstanding contribution to the understanding of Aerodynamics of Slab delta wings at high Mach numbers [9,10]. More recently, extensive work was carried out on Aerospike Engine research leading to important publications in this area [11,12,13].…”

Section: Major R and D Work: Past And Futurementioning

confidence: 99%

Design and Development of a New 0.5m Hypersonic Wind Tunnel Facility at Indian Institute of Science

Padbidiri,

Shivashankar,

Nagarjun

et al. 2023

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This paper describes the realization of a 0.5m hypersonic wind tunnel, second largest of its kind in India, at the High Speed Wind Tunnel Complex at Indian Institute of Science (IISc), Bangalore. The project was fully funded by the Aerodynamics Panel of AR & DB. There were two major activities associated with the project. One of them pertains to the "Strengthening of the existing 0.3m Hypersonic Wind Tunnel "(originally built in 1985) by adding a new high pressure air compressor, a cascade of high pressure air storage tanks, vacuum pumps and vacuum tanks and another related to establishing "an Additional 0.5m Hypersonic Wind Tunnel Leg". Preliminary commissioning trials of the new facility at low stagnation pressures were conducted in October 2013. Subsequently several hypersonic blow downs were carried out on a variety of models at Mach 8.0. Pitot probe measurements performed in the test section confirmed that the flow Mach number was close to Mach 8.0. The total run time measured was around 10 seconds. Thus, a large 0.5m hypersonic wind tunnel was indigenously designed, developed and commissioned in about 30 months at a cost of Rs.6 Crores. The facility was inaugurated by Prof. R. Narasimha in the presence of a large gathering of leading aerospace scientists in the country, on 8th April 2014.

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Aerodynamics of delta wings with flaps at hypersonic speeds

Ramesh

2002

Aeronaut. j.

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Control surface effectiveness is an important parameter for any aeroplane. For a hypersonic aircraft, though the power required to operate the flaps is determined by low speed flying conditions, it is imperative to know the effect of flaps at hypersonic speeds. Hence, studies have been done on this topic by aerodynamicists for over 40 years. In spite of this, only a limited data is available in the literature on this subject.This paper discusses the experimental study of the effect of sweep on the aerodynamic characteristics of thin slab delta wings with flaps at hypersonic speeds. For the purpose of this investigation, a novel special thin six-component balance, which has a thickness of 4mm and can be housed inside wings with 8mm thickness, has been designed. The wings had a sweep of 76°, 70° and 65°, t/c of 0.053 and flaps with 12% of wing area and 12% of wing chord. Testing were done at Mach 8.2, Re number of 2.13 x 106 (based on chord), from α = –12° to 12° and flap angle of 20°, 30° and 40°. Separation lengths, measured from Schlieren pictures, clearly show that there is ‘no appreciable’ effect of sweep on them. Also, using a simple local flow field calculation, the separation has been identified to be transitional in nature. These features of separation reflect in the force data. Because of the small separation length, the flaps (inspite of their small size) were very effective in generating additional CN, CM and Cl, which increased with increase in flap angle. In general, the CN, CM and XCP were unaffected by sweep for symmetric flap deflection at positive incidences and asymmetric flap case. For symmetric flap case at negative incidences, only CN was not influenced by the sweep but CM decreased and XCP moved upstream as the sweep is decreased. The wing with lower sweep produces higher CA and lower (L/D)max for both symmetric and asymmetric flaps. The rolling moment and adverse yaw increased with decrease in sweep for asymmetric flap deflection. Newtonian theory is shown to be incapable of predicting the effect of sweep on Cl, Cn and on the incremental values of CN, CM and CA.In conclusion, it can be said that a small flap is generally adequate for hypersonic aeroplanes provided they operate at altitudes where transitional and turbulent separation can be expected to occur. This would make the flaps effective and thus enable ample control authority.

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On the aerodynamic characteristics of thin slab delta wings at hypersonic speeds — part 1: interference of lee side bodies

Cited by 4 publications

References 7 publications

Thin flat balances for testing thin delta wings at hypersonic speeds

Thin flat balances for testing thin delta wings at hypersonic speeds

Design and Development of a New 0.5m Hypersonic Wind Tunnel Facility at Indian Institute of Science

Aerodynamics of delta wings with flaps at hypersonic speeds

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