Erhan Pulat - Academia.edu (original) (raw)

Papers by Erhan Pulat

Heat and Mass Transfer, 2004

In this study, airflow and temperature fields in an office room with a table and a sitting person... more In this study, airflow and temperature fields in an office room with a table and a sitting person are computed to predict the thermal comfort by means of percent dissatisfaction (PD). The office room is ventilated with a wall type air conditioning unit for winter condition and the flow is considered to be turbulent, steady, incompressible, and two-dimensional. Govern ing equations are solved by using commercial computational flu id Dynamics (CFD) code of ANSYS15 Fluent. Firstly, grid independency study is evaluated by using Standard k-ε (Std. k-ε) model with standard wall function approach, and then five RANS based two-equations turbulence models and near-wall modelling approaches are compared and validated by using well-known Annex20 test room. Although all k-ε based models exh ib it similar performance, Std. k -ε model with std. wall function approach was preferred due to common usage and its numerical robus tness. Computations are performed for nine different cases including thre...

International Journal of Energy Research, 2008

In this paper, the effect of various system parameters on horizontal ground source compression re... more In this paper, the effect of various system parameters on horizontal ground source compression refrigeration machine (CRM) performance is studied experimentally in Bursa, Turkey. A ground heat exchanger (GHE) system connected to CRM in a test room in the air conditioning and refrigeration laboratory of Uludag University has been designed and constructed. This system was tested for space cooling in August and September 2004 and performance tests were performed during this period. Overall, system mainly consists of the GHE (GHE-water circuit) and CRM (CRMrefrigerant circuit). Refrigerant is R134a. Hourly variations of inlet and outlet water temperatures, extracted heat from test room, rejected heat to ground, compression ratio, total power consumption, and coefficient of performance (COP) values for both whole system and only CRM are obtained. Thermal properties of soil are also estimated by using experimental data and theory. Cooling load of test room and rejected heat to ground, and all COP values are also presented. Finally, heat rejection rate to ground with respect to leaving water temperature from GHE is given. The COP of the overall system changes between 2 and 2.5, also CRM COP values are in the range of 3 and 3.86. Copyright

Kocaeli Journal of Science and Engineering

Uludağ University Journal of The Faculty of Engineering

International Communications in Heat and Mass Transfer

Numerical Heat Transfer Part B Fundamentals, Dec 1, 2011

Bu çalışmada IEA (International Energy Agency) Annex20 odasının havalandırılmasında ısıl konfor H... more Bu çalışmada IEA (International Energy Agency) Annex20 odasının havalandırılmasında ısıl konfor Hesaplamalı Akışkanlar Dinamiği (HAD) metodu kullanılarak araştırılmıştır. Oda içerisindeki hava akışı iki boyutlu, sıkıştırılamaz ve türbülanslıdır. İlk olarak oda içerisindeki akış ve sıcaklık dağılımları k-ε ve k-ω tabanlı türbülans modelleri kullanılarak elde edilmiş ve uygun türbülans modeli belirlenmeye çalışılmıştır. Bu amaçla ANSYS-Fluent yazılımı kullanılmıştır. Belirlenen türbülans modeli yüzde memnuniyetsizlik (Draft oranı) indeksiyle birlikte kullanılarak oda içindeki ısıl konfor sayısal olarak hesaplanmıştır. Böylece literatürde oda havalandırması çalışmalarında sıklıkla başvurulan IEA Annex20 odası konfor çalışmasına uyarlanmış ve oda içerisindeki konforlu bölgeler tespit edilmeye çalışılmıştır. In this study, thermal comfort in vantilation of IEA (International Energy Agency) Annex20 room is investigated with using CFD (Computational Fluid Dynamics) method. Air flow inside ...

Energy and Buildings, 2015

Cooling of Electronic Systems, 1994

Numerical Heat Transfer, Part B: Fundamentals, 2011

International Journal of Refrigeration, 2012

uludag.edu.tr

Uluda?? ??niversitesi M??hendislik-Mimarl??k Fak??ltesi Dergisi, Cilt 13, Say?? 2, 2008 69 ??ARPA... more Uluda?? ??niversitesi M??hendislik-Mimarl??k Fak??ltesi Dergisi, Cilt 13, Say?? 2, 2008 69 ??ARPAN D??KD??RTGEN B??R HAVA JET??NDE T??RB??LANS MODELLER??N??N KAR??ILA??TIRILMASI VE ??LG??L?? PARAMETRELER??N ISI TRANSFER??NE ETK??LER?? Serdar GE????M* Erhan PULAT ...

Heat and Mass Transfer, 2014

Numerical Heat Transfer Part A-applications, 2008

In this study, heat transfer characteristics in the single slot jet impinging cooling process of ... more In this study, heat transfer characteristics in the single slot jet impinging cooling process of constant heat flux surface are numerically investigated. It is assumed that the flow is turbulent, two-dimensional and in steady state. Governing equations are solved by using Galerkin finite element method by employing five two-equation turbulence models based on Reynolds-averaged Navier-Stokes (RANS) approach. Although the most

Renewable and Sustainable Energy Reviews, 2009

Textile sector of Turkey has a large production capacity and it is one of the important sectors. ... more Textile sector of Turkey has a large production capacity and it is one of the important sectors. Many industrial heating processes generate waste energy in textile industry. Therefore, there is a tremendous waste-heat potential to utilize in textile applications. This study assesses the potential of waste-heat obtained from particularly dyeing process at textile industry in Bursa where textile center of Turkey. Energy consumptions could be decreased by using of waste-heat recovery systems (WHRSs). A thermodynamic analysis is performed in this study. An exergy-based approach is performed for optimizing the effective working conditions for WHRSs with water-to-water shell and tube heat exchanger. The payback period is found to be less than 6 months. The variations of the parameters which affect the system performance such as waste-water inlet temperature, mass flow rate, cooling water inlet pressure and dead state conditions are examined respectively. The results of the analysis show that the exergy destruction rate and economical profit increase with increasing of mass flow rate of the waste water. Similarly, exergy destruction rate, effectiveness and economical profit increase while the second law efficiency decreases as the waste-water inlet temperature increases. #

Heat and Mass Transfer, 2005

Theoretical and experimental study of the paper drying process are presented. A mathematical mode... more Theoretical and experimental study of the paper drying process are presented. A mathematical model developed for combined heat ad mass transfer analysis of paper drying is given for both impinging air jets and through air drying methods. In this model, it is simply assumed that during the drying period of the paper has porous media and on the drying surface the vapour pressure of the evaporating liquid remains at a quasi-saturated value corresponding to the temperature of the liquid. The calculated transient paper temperatures in both methods agree well with the experimental results.