The compressible jet plume emerging from a planar convergent–divergent nozzle containing a separation shock is investigated experimentally and numerically. The investigation encompasses exit-to-throat area ratios (Ae=At) from 1.0 to 1.8 and nozzle pressure ratios from 1.2 to 1.8. Experiments were conducted in a variable-geometry nozzle facility, and computations solved the Reynolds-averaged Nav...

In this paper, the flow characteristics due to asymmetric sudden contraction is discussed based on experimental investigation when the flow through the contracted section passed from subcritical to critical flow. The experiments are conducted on a 30 cm wide, 45 cm deep and 10.5 m long laboratory flume. Different contraction ratios are considered. Different lengths of the contracted section are...

suspended particles with aerodynamic diameters not greater than 2.5 μm (pm2.5) were sampledat the urban background, regional background and urban traffic points in southern poland. in total, 120 sampleswere collected between 2nd august 2009 and 27th december 2010. 16 polycyclic aromatic hydrocarbons (pahs)and organic carbon (oc) were determined in each sample. the samples were collected with a ...

Studies of the energy return on investment (EROI) for oil production generally rely on aggregated statistics for large regions or countries. In order to better understand the drivers of the energy productivity of oil production, we use a novel approach that applies a detailed field-level engineering model of oil and gas production to estimate energy requirements of drilling, producing, processi...

How do we know which energy technologies or resources are worth pursuing and which aren’t? One way to answer that question is to compare the energy return of a certain technology—i.e., how much energy is remaining after accounting for the amount of energy expended in the production and delivery process. Such energy return ratios (the most famous of which is energy return on investment (EROI)) f...

The thermal balance analysis is a useful method to determine energy distribution and efficiency of internal combustion (IC) engines. In engines cooling concepts, estimation of heat transfer to brake power ratio, as one of the most significant performance characteristics, is highly demanded. In this paper, investigation of energy balance and derivation of specific heat rejection is carried out e...

The goal is to help create smooth energy-optimal monophasic pulse waveforms for defibrillation using the Luo-Rudy cardiomyocyte membrane computer model. The waveforms were described with the help of the piecewise linear function. Each line segment provides a transition from one present level of the transmembrane potential to the next with a minimal energy value. The duration of the last segment...