Wing Thickness Optimization for Box Wing Aircraft

Author(s): Jemitola P. Olugbeji, Okafor E. Gabriel*, Godwin Abbe

Journal Name: Recent Patents on Engineering

Volume 14 , Issue 2 , 2020

Become EABM
Become Reviewer
Call for Editor

Graphical Abstract:


Background: In the interest of improving aircraft performance, studies have highlighted the benefits of Box wing configurations over conventional cantilever aircraft configuration. Generally, the greater an aircraft's average thickness to chord ratio (τ), the lower the structural weight as well as volumetric capacity for fuel. On the other hand, the lower the (τ), the greater the drag reduction. A review of patents related to the Box-wing aircraft was carried out. While methodologies for optimizing wing thickness of conventional aircrafts have been studied extensively, limited research work exist on the methodology for optimizing the wing thickness to chord ratio of the Box wing aircraft configurations.

Methods: To address this gap, in this work, a two stage optimization methodology based on gradient search algorithm and regression analysis was implemented for the optimization of Box wing aircrafts wing thickness to chord ratio. The first stage involved optimizing the All Up Mass (AUM), Direct Operating Cost (DOC) and Zero Lift Drag Coefficients (CDO), with respect to the aft and fore sweep angle for some selected τ values. At the second stage, a suitability function (γ) was optimized with respect to the aft and fore sweep angle for some selected τ values. A comparative study was further carried out using the proposed methodology on similar size cantilever wing aircraft.

Result: From the result, an optimal τ value was reached. Also the τ value for the cantilever aircraft found based on the proposed methodology was similar to the true τ value of the adopted aircraft, thereby validating the methodology.

Conclusion: Based on the optimal τ value reached from this work, the Box wing aircraft are suitable for thin airfoils.

Keywords: Box wing aircraft, optimization, response surface, wing thickness, airfoils, chord ratio (τ).

J. Wolkovitch, "The joined wing: an overview", J. Aircr., vol. 23, pp. 161-178, 1986.
I. Kroo, J.W. Gallman, and S.C. Smith, "Aerodynamic and structural studies of joined-wing aircraft", J. Aircr., vol. 28, no. 1, pp. 74-81, 1991.
R.K. Nangia, M.E. Palmer, and C.P. Tilman, "Unconventional high aspect ratio joined-wing aircraft with aft and forward swept wing tips", AIAA-2003-0605", 41st Aerospace Sciences Meeting, Nevada, January 2003,
W.P. Henderson, and J.K. Huffman, Aerodynamic characteristic of a tandem wing configuration at a mach number of 0.30.Report X-72779, NASA, March 1975.,
V.S. Eger, Light duty box-wing aeroplane. U.S. Patent 5,503,352, April 2, 1996.,
R. Carlos, “Aircraft having a lambda-box wing configuration”.U.S. Patent 20110180660 A1, July 28, 2011.,
J. Wolkovitch, “Joined wing aircraft”.U.S. Patent 4,365,773, December 28, 1982.,
L. Miranda, “Boxplane wing and aircraft”. U.S. Patent 3,834,654,September 10, 1973,
A. Hernadi, “Method for improvement of the box wing aircraft concept and corresponding aircraft configuration”.WIPO Patent Cooperation Treaty 2016048211 A1, March 31, 2016,
L. Prandtl, “Induced drag of Multiplanes”.Technische Berichte, Vol. III, No. 7, 1924,
A, Frediani, “The Prandtlwing, Lecture series on innovative configurations and advanced concepts for future civil aircraft”, Von Karman Institute, VKI 2005-06, 2005.,
K. Balaji, S. Rathnavel, J. Vinoth, and V. Siva, "Experimental investigation of conceptual box wing aircraft", Int. J. Res. Aero Mech. Eng., vol. 4, no. 4, pp. 76-84, April 2016.
H. Smith, and P. Jemitola, A - 9 Box Wing Medium Range Airliner - Project Specification., Department of Aerospace Engineering, Cranfield University: Cranfield, 2009.
P.O. Jemitola, Conceptual Design and Optimization Methodology for Box Wing Aircraft., Department of Aerospace Engineering, Cranfield University: Cranfield, 2012.
D. Howe, Aircraft Loading and Structural Layout., Professional Engineering Publishing Limited: London, 2004.
L. Jenkinson, D. Rhodes, and P. Simpkin, Civil Jet Aircraft Design., Arnold Publishers: UK, 1999.
S.F. Hoerner, Fluid Dynamic Drag: Practical Information on Aerodynamic Drag and Hydrodynamic Resistance., Hoerner Fluid Dynamics: New Jersey, USA, 1965.
J. Roskam, Preliminary Calculation of Aerodynamic., Thrust and Power Characteristics, Roskam Aviation and Engineering Corporation: Kansas, USA, 1990.
J. Roskam, Airplane Cost Estimation: Design, Development., Manufacturing and Operating, Roskam Aviation and Engineering Corporation: Kansas, USA, 1990.
B. Pamadi, Performance, Stability, Dynamics and Control of Airplance., 2nd ed AIAA: Virginia, USA, 2004.

Rights & PermissionsPrintExport Cite as

Article Details

Year: 2020
Page: [242 - 249]
Pages: 8
DOI: 10.2174/1872212113666190206123755
Price: $25

Article Metrics

PDF: 10