Results 21 to 30 of about 62,356 (296)

Simultaneous estimation of heat flux and heat transfer coefficient in irregular geometries made of functionally graded materials

International Journal of Thermofluids, 2020
A numerical inverse analysis based on explicit sensitivity coefficients is developed for the simultaneous estimation of heat flux and heat transfer coefficient imposed on different parts of boundary of a general irregular heat conducting body made of ...
Farzad Mohebbi, Ben Evans
doaj   +1 more source

An Inverse Approach to Estimate Heat Transfer Coefficients of 122 mm Medium-Range Missile During Correction Engine Operation [PDF]

Problemy Mechatroniki, 2014
This paper presents an inverse approach to estimate the heat transfer coefficients on the inner and the outer sides of a cylindrical shield made of R35 steel containing a gas-dynamic control block of a 122 mm medium-range missile during the combustion of
Janusz ZMYWACZYK, Piotr KONIORCZYK, Marek PREISKORN, Bogdan MACHOWSKI   +3 more
doaj   +1 more source

Commuting Outer Inverses

Advances in Linear Algebra & Matrix Theory, 2013
The group, Drazin and Koliha-Drazin inverses are particular classes of commuting outer inverses. In this note, we use the inverse along an element to study some spectral conditions related to these inverses in the case of bounded linear operators on a Banach space.
Muneo Chō, Gabriel Kantún-Montiel
openaire   +2 more sources

The expansion factors of an outer automorphism and its inverse [PDF]

Transactions of the American Mathematical Society, 2007
A fully irreducible outer automorphism ϕ \phi
Handel, Michael, Mosher, Lee
openaire   +3 more sources

Bordering method to compute Core-EP inverse

Special Matrices, 2018
Following the work of Kentaro Nomakuchi[10] and Manjunatha Prasad et.al., [7] which relate various generalized inverses of a given matrix with suitable bordering,we describe the explicit bordering required to obtain core-EP inverse, core-EP generalized ...
Prasad K. Manjunatha, Raj M. David
doaj   +1 more source

Unsteady heat exchange at the dry spent nuclear fuel storage

Nuclear Engineering and Technology, 2017
Unsteady thermal processes in storage containers with spent nuclear fuel were modeled. The daily fluctuations of outer ambient temperatures were taken into account.
Svitlana Alyokhina, Andrii Kostikov
doaj   +1 more source

Theoretical Study of Gamma-ray Pulsars [PDF]

Journal of Astronomy and Space Sciences, 2016
We use the non-stationary three dimensional two-layer outer gap model to explain gamma-ray emissions from a pulsar magnetosphere. We found out that for some pulsars like the Geminga pulsar, it was hard to explain emissions above a level of around 1 GeV.
Kwong Sang Cheng, Jumpei Takata
doaj   +1 more source

The outer generalized inverse of an even-order tensor

, 2020
Necessary and sufficient conditions for the existence of the outer inverse of a tensor with the Einstein product are studied. This generalized inverse of a tensor unifies several generalized inverses of tensors introduced recently in the literature ...
Ji, Jun, Wei, Yimin
core   +1 more source

Theoretical and Experimental Heat Transfer in Solid Propellant Rocket Engine [PDF]

Journal of Aerospace Technology and Management, 2019
Accurate determination of heat flux is an important task not only in the designing aspect, but also in the performance analysis of rocket engines. In this purpose, this work deals with the heat flux determination in a combustion chamber through the ...
Izabel Cecilia Ferreira de Souza Vicentin, Carlos Henrique Marchi, Antonio Carlos Foltran, Diego Moro, Nicholas Dicati Pereira da Silva, Marcos Carvalho Campos, Luciano Kiyoshi Araki, J. Aerosp. Technol. Manag., São José dos Campos, v11, e3819, 2019 https://doi.org/10.5028/jatm.v11.1066 ORIGINAL PAPER 1.Universidade Federal do Paraná – Setor de Ciências Exatas – Engenharia Mecânica – Curitiba/PR – Brazil. 2.Universidade Positivo – Engenharia Mecânica – Curitiba/PR – Brazil. *Correspondence author: izabeldesouza@gmail.com Received: Feb. 6, 2018 | Accepted: Oct. 30, 2018 Section Editor: T John Tharakan ABSTRACT: Accurate determination of heat flux is an important task not only in the designing aspect, but also in the performance analysis of rocket engines. In this purpose, this work deals with the heat flux determination in a combustion chamber through the inverse method. In this approach, the transient heat flux is determined from the experimental temperature data measured at the outer sidewall of the rocket engine. In this work the physical phenomenon was modeled by the transient one-dimensional heat equation in cylindrical coordinates and the material properties of the chamber were considered constant. Furthermore, the model is solved using the inverse heat conduction problem with least squares modified by the addition of Tikhonov regularization term of zero-order. Moreover, the sensitivity coefficients were obtained by Duhamel’s theorem. Through the regularization parameter, it was able to generate acceptable results even when using data with considerable experimental errors. KEYWORDS: Combustion chambers, Heat flux, Heat conduction, Ill-posed problems. INTRODUCTION In a thrust chamber (nozzle and combustion chamber), the amount of energy transferred as heat to the chamber walls is between 0.5% and 5% of the total generated energy (Sutton 1992). Nevertheless, this amount could be enough to cause structural failure. Thus, to prevent the chamber and nozzle walls from failing, it is necessary to predict the heat flux accurately. Furthermore, accurate determination of heat flux is also important in the calculation of rocket engine performance and for the cooling system design. Convective and radiative heat transfer must be determined for characterization of total heat flux. The convective heat transfer coefficient typically depends on many fluid physical properties. The computation of the radiation heat transfer must be accounted by the surfaces emissivity and the absorption and scattering coefficients of the fluid mixture. However, information about these parameters is not always easily found. Considering the propellant applied in this work (potassium nitrate with sucrose, KNSu), the combustion products that affects radiation heat transfer are predominantly Theoretical and Experimental Heat Transfer in Solid Propellant Rocket Engine Izabel Cecilia Ferreira de Souza Vicentin1,*, Carlos Henrique Marchi1, Antonio Carlos Foltran1, Diego Moro1,2, Nicholas Dicati Pereira da Silva1, Marcos Carvalho Campos1, Luciano Kiyoshi Araki1, Alysson Nunes Diógenes   +7 more
doaj   +3 more sources

Rank equalities related to a class of outer generalized inverse [PDF]

, 2019
[EN] In 2012, Drazin introduced a class of outer generalized inverse in a ring R, the (b, c)-inverse of a for a,b,c is an element of R and denoted by a(parallel to(b,c)). In this paper, rank equalities of A(k)A(parallel to(B,C)) - A parallel to((B,C))A(k)
Chen, Jianlong, Xu, Sanzhang, Benítez López, Julio, Chen, Xiaofeng   +3 more
core   +1 more source