Sökning: "overexpanded"

Hittade 5 avhandlingar innehållade ordet overexpanded.

  1. 1. Supersonic flow separation with application to rocket engine nozzles

    Författare :Jan Östlund; KTH; []
    Nyckelord :turbulent; boundary layer; shock wave; interaction; overexpanded; rocket nozzle; flow separation; control; side-load; experiments; models; review;

    Sammanfattning : The increasing demand for higher performance in rocketlaunchers promotes the development of nozzles with higherperformance, which basically is achieved by increasing theexpansion ratio. However, this may lead to flow separation andensuing instationary, asymmetric forces, so-called side-loads,which may present life-limiting constraints on both the nozzleitself and other engine components. LÄS MER

  3. 2. Flow Processes in Rocket Engine Nozzles with Focus on Flow Separation and Side-Loads

    Författare :Jan Östlund; KTH; []
    Nyckelord :turbulent; boundary layer; shock wave; interaction; intermittent; overexpanded; rocket nozzle; flow separation; side-load; models; criteria; prediction; review;

    Sammanfattning : .... LÄS MER

  4. 3. Modal Analysis of Supersonic Flow Separation in Nozzles

    Författare :Ragnar Larusson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Separated Nozzle Flow; Dynamic Mode Decomposition; Hybrid RANSLES; CFD; Modal Analysis; Arnoldi;

    Sammanfattning : Operating a convergent-divergent nozzle under overexpanded conditions can lead to supersonic flow separation in the divergent section of the nozzle. In this case, an attached oblique shock wave forms at the separation base. LÄS MER

  5. 4. Detached Eddy Simulation for Aerospace Applications

    Författare :Gonzalo Montero Villar; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Evolutionary algorithms; Synthetic turbulence; Chorochronic; POD based phase-lag; Sliding grid; Nozzle flow separation; Hybrid RANS LES; Phase-lagged boundary conditions; Stochastic optimization; CFD; LODI;

    Sammanfattning : With the continuous growth in air traffic that we see nowadays, comes an increase in the requirements needed to be satisfied in order to certify an aircraft for operation. These stricter regulations affect aspects such as CO2 emissions, sound pollution and so on, pushing manufacturers to aim for lighter, more efficient, more robust designs. LÄS MER

  7. 5. The expanded skin in breast reconstruction : an experimental and clinical study

    Författare :Michael Olenius; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Tissue expansion; capsular contraction; rapid and slow expansion; mitotic activity; epidermal thickness; skin thickness; collagen diameter; skin properties; insulin-like growth factorStockholm 1995 ISB;

    Sammanfattning : Tissue expansion has become one of the routine methods in breast reconstruction. It is a safe and easy method, which is well accepted by the patient. Clinical reports are numerous, but morphological changes are still not thoroughly investigated. LÄS MER