Results 261 to 270 of about 352,444 (305)

Control of Flame Oscillations with Equivalence Ratio Modulation

Journal of Propulsion and Power, 1999
A novel technique for controlling oscillating combustion is proposed and demonstrated. For oscillations that exist over a limited range of equivalence ratios, we suggest that periodic modulation around the unstable condition can effectively avoid the oscillating condition, but otherwise produces the desired timeaverage equivalence ratio.
Geo A. Richards, Michael Janus, Edward H. Robey   +2 more
openaire   +1 more source

Optical equivalence ratio sensors for gas turbine combustors

Proceedings of the Combustion Institute, 2005
Chemiluminescence sensing is shown to be a useful approach for monitoring local, reaction zone equivalence ratios. For natural gas combustion, the ratio of CH∗ to OH∗ chemiluminescence is shown to be a useful indicator of equivalence ratio (ϕ). The ratio of peak intensities (CH∗/OH∗) is shown to monotonically increase with ϕ for the operating regime ...
T.M. Muruganandam, B.-H. Kim, M.R. Morrell, V. Nori, M. Patel, B.W. Romig, J.M. Seitzman   +6 more
openaire   +1 more source

Pneumatic suspension damping characterisation with equivalent damping ratio

International Journal of Heavy Vehicle Systems, 2012
The damping property of a pneumatic suspension with orifice-type fluidic resistance is characterized in this study. The nonlinear and linear models for the suspension system are first formulated and experimentally verified. The verified linear model is employed to derive a new pneumatic damping measure, equivalent damping ratio, based on which a ...
Yin, Zhihong, Cao, Dongpu, Khajepour, Amir, Ebrahimi, Babak, Guo, Konghui   +4 more
openaire   +1 more source

Chemiluminescence as a Measurement of Local Equivalence Ratio

38th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2002
Measurements of the chemiluminescence of OH*, CH*, and C2* in laminar laboratory propane/air flames and a liquid-fueled model combustor are presented. Ratios of the emission intensity for the three species are a strong function of equivalence ratio.
Michael Brown, Terrence Meyer, Geoffrey Sturgess, Joseph Zelina, James Gord   +4 more
openaire   +1 more source

Laminar premixed flame response to equivalence ratio oscillations

Combustion and Flame, 2005
Self-excited oscillations in low emission, premixed combustion systems are often caused by feedback between unsteady heat release rates and reactive mixture equivalence ratio perturbations. This paper presents an analysis of the flame response to equivalence ratio perturbations, showing that the heat release response is controlled by the superposition ...
Ju Hyeong Cho, Tim Lieuwen
openaire   +1 more source

Housing Careers, Price–Rent Ratios and Rental Equivalence

Housing, Theory and Society, 2012
Abstract This paper analyses price–rent (PR) ratios under different housing career structures. A housing market with three segments for owner-occupation and a segment with rental housing is applied. A housing career is characterized by how households move between rentals and owner-occupied housing. While rents are completely passed through to the house
Trond-arne Borgersen, Dag einar Sommervoll   +1 more
openaire   +1 more source

In-Cylinder Equivalence Ratio Measurements in an EGR Equipped Engine

Journal of Engineering for Gas Turbines and Power, 2010
A single-cylinder natural gas fueled engine equipped with an exhaust gas recirculation (EGR) system was ignited using a laser. The broadband emission from the spark kernel was spectrally resolved, and the peaks corresponding to Hα, N, and O atoms were measured for a range of conditions with global equivalence ratios ranging between 0.6 and 1.0 and for ...
Sreenath B. Gupta, Bipin Bihari, Munidhar Biruduganti, Raj Sekar   +3 more
openaire   +1 more source

Equivalence ratio variation and combustion instability in hybrid rocket

Journal of Mechanical Science and Technology, 2019
In this paper, a series of combustion tests using PMMA/O2 was conducted to examine the initiating characteristics of low frequency instability (LFI) in relation to the changes in both flow and combustion conditions. By selecting parameters such as the oxidizer mass flow rate, fuel grain length, and mixing ratio of mixture oxidizer composed of oxygen ...
Dong Eun Lee, Changjin Lee
openaire   +1 more source

Equivalence ratio and constriction effects on RBCC thrust augmentation

Acta Astronautica, 2011
Abstract A theoretical analysis of a variable area rocket based combined cycle engine with and without simultaneous mixing and combustion is presented. The flowfield is solved using a steady, quasi-one-dimensional, inviscid control volume formulation with combustion effects included via a generalized equilibrium calculation.
M. Koupriyanov, J. Etele
openaire   +1 more source

Local effective length factor in the equivalent slenderness ratio

Canadian Journal of Civil Engineering, 1995
The Canadian Standard S16.1 specifies an equivalent slenderness ratio to be used when determining the compressive resistance of a built-up member when buckling occurs about an axis perpendicular to the interconnectors. This equivalent slenderness ratio is the square root of the sum of the squares of the slenderness ratio of the built-up member acting ...
Murray C. Temple, Ghada Elmahdy
openaire   +1 more source