Sökning: "detonation"

Visar resultat 1 - 5 av 19 avhandlingar innehållade ordet detonation.

1. 1. Flame Dynamics and Deflagration-to-Detonation Transition

   Författare :Damir Valiev; Börje Johansson; R. J. M. (Rob) Bastiaans; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; flame; premixed; instability; fractal; deflagration; detonation; DDT; simulation; Physics; Fysik;

   Sammanfattning : Various premixed flame phenomena are studied by means of direct numerical simulations of the complete system of hydrodynamic equations. Rigorous study of flame dynamics is essential for all premixed combustion problems where multidimensional effects cannot be disregarded.The present thesis consists of six parts. LÄS MER

3. 2. Magnetic deflagration and detonation in crystals of nanomagnets

   Författare :Oleksii Iukhymenko; Claude Dion; Javier Tejada; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanomagnets; magnetic deflagration; front instability; Zeeman energy; magnetic instability; magnetic detonation; weak detonation; Physics Of Matter; materiefysik;

   Sammanfattning : In this thesis we cover the dynamics of the macro magnetic transformations (spin avalanches) in crystals of molecular nanomagnets, also known as magnetic deflagration and detonation.Taking a single-molecule Hamiltonian, we calculate the dependence of Zeeman energy and the activation energy as a function of an external magnetic field at different angles relative to the easy axis of the crystal. LÄS MER

4. 3. The role of Landau-Darrieus instability in flame dynamics and deflagration-to-detonation transition

   Författare :Damir Valiev; Börje Johansson; Vladimir Karlin; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flame; premixed; instability; front; Landau; Darrieus; fractal; freely; deflagration; detonation; transition; DDT; modeling; simulation; Other materials science; Övrig teknisk materialvetenskap;

   Sammanfattning : The role of intrinsic hydrodynamic instability of the premixed flame (known as Landau-Darrieus instability) in various flame phenomena is studied by means of direct numerical simulations of the complete system of hydrodynamic equations. Rigorous study of flame dynamics and effect of Landau-Darrieus instability is essential for all premixed combustion problems where multidimensional effects cannot be disregarded. LÄS MER

5. 4. Engine Knock: Characteristics and Mechanisms

   Författare :Klaas Burgdorf; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; SWACER; SI engines; quasi-detonation; autoignition; developing detonation; knock;

   Sammanfattning : Knock in SI engines limits both power density and fuel conversion efficiency. The main mechanisms with the potential to generate the cylinder pressure fluctuations generally observed during knocking combustion are discussed. It is reasoned that some mechanisms of flame acceleration can further amplify a shock wave generated by autoignition. LÄS MER

7. 5. Post-Detonation Afterburning of High Explosives

   Författare :Katja Fedina; Strömningsteknik; []
   Nyckelord :Explosives; Combustion; LES; Finite rate chemistry; Explosives; Combustion; LES; Finite rate chemistry; Height of Burst;

   Sammanfattning : High performance of an explosive compound with respect to afterburning requires sufficient combustible properties of the explosive, and a careful determination of the most appropriate charge positioning to achieve the desired afterburning effect. Understanding the physical processes of post-detonation afterburning and how these are affected by the surroundings, e. LÄS MER